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Understanding Stroke

One must remember that what I’m saying is just my theory, not necessarily the mathematical facts that apply to you, your style, or the current technical effects you may be applying at any given time. I believe that once you understand this theory you will have a better understanding of how to tune a machine and just how many machines you want to set up per tattoo setting. And which particular set of needles to use with each machine per technique being applied.
This theory is based on the idea that the tattooer should control every thing related to tattooing, and that comfortable and controllable hand speed has priority value. This theory will help you control the many different types of lining, shading, and coloring techniques, and even explains how to get the once hard to master, but now totally possible and easy to do, transparent layered effects.
This theory shows you how to use “lining” machines for shading and how to use your “shader” machines for tight details. Another thing you’ll find is, there are no rules that say you have to use a liner machine for lining, or a shader for shading only. You should use the machine for the effect you want, not just what the name of the machine implies. As long as you equate the name of your machines to reflect the stroke length, you can call your machine(s) anything you’d like.

I hope to open the doors to techniques that in the past have been very hard to do. If you don’t understand this theory or something like it, I believe your tools (needles and machines) will limit and control your artistic destiny, maybe even damn you to being a struggling craftsman your entire career. You can only be as good as your tools and wisdom will allow you to be. You’ll never be a master tattooer until you master your tattools. Understanding this theory will help you do that.

Even though there are many different sizes of needle groupings, I’ll only be describing some of the most common shapes. I’ll describe a single needle liner, a small round, a large round , flats, magnums, and a 75 (15 x 5) needle superflat.
In order to understand stroke length a couple of constants need to be set. For this example, Hand speed, Distance traveled, and Stroke length will be constant. Lets say the distance traveled will be 1 inch, Hand speed (this is the speed the needles pass over the skin as they are tattooing) will be 3 seconds of elapsed time per 1 inch of travel, and the stroke length will be, .125 of an inch, ( 1/8 of an inch).

Stroke length can be described two ways. Stroke length can be the distance between the armature bar and the front coil post. And or the stroke length can be measured by the distance between the center of one needle mark to the center of the next needle mark, when the needles traverse the skin under constant hand speed.

Stroke Speed, is the time it takes for the needles to make one complete in and out cycle.

The stroke length I’m talking about for this example is not the distance between the armature bar and the coil post, we’ve already established that stroke length to be .125 in. The stroke length we’re talking about here is the distance from center to center of the needle marks as you draw a line while moving your hand at the predetermined speed of 3 seconds per 1 inch of travel. If your machine is running at 60 strokes per minute and the line takes 3 seconds to complete there will have been 180 strokes per inch. That equates to approximately an 80% over lap of needle marks.

You can tattoo with any size of needle group and still have the same stroke speed. But if your stroke length remains the same, your predictable results are very limited, and the risk of over tattooing increases in proportion to the increase in size of needle group being used.
On the other hand, if you increase the stroke length (slow down stroke speed) in proportion to the increase in needle group width, and you slow your hand speed to compliment the stroke speed, you can tattoo very efficiently with very large groups of needles with no detectable increase in skin damage.
If you understand that aspect, it is easy to understand how a fast stroke speed (short stroke length) contributes to the over tattooing that happens when you use a stroke length that is too fast (short stroked) for the size of needle group being used. The shorter the stroke length the faster the stroke speed, and the faster your hand needs to move to keep from overdosing the skin with unwanted needle marks.

Assuming you are moving the needles in the fashion to get a line, as the machine’s reciprocating action moves the needles in and out of the skin, and the needles are leaving their mark, there are two ways to get the needle tracks close enough to each other to leave a solid line. One way is to have a short stroke length, which equates to a faster stroke speed. Remember, “Stroke Speed” is the time it takes for the needles to make one complete in and out cycle.
The other option for getting the needle marks close enough together to from a line, is to have a slower hand. Slower hand speed is more effective and provides more technical opportunities than a fast hand and short stroke machine can accommodate.
The right method, first and foremost, is to move your hand at a comfortable and controllable pace. But, (and this is the biggest “but” in the industry), the option to slow your hand speed down is available only if you are able, and know how to slow down the stroke speed, (And you don’t do it by adjusting the power supply). In other words, lengthen the distance from center to center of the needle tracks.
When a faster or slower stoke speed is needed, you control that stoke speed by increasing or decreasing the stroke length. Which is hard to do with a fixed spring machine, and that is the exact reason behind the development of our K-model tattoo machine.

A couple of the things you might see when you casually look at how needle tracks overlap one another when stroke length (stroke speed) is too short (too fast) for the proper hand speed, are either blown-out lines, or very weak lines. And the skin surface maybe slightly torn, like a minor scratch, or even a sever ditch like gouge.
But when you take an in-depth look at how a longer (slower) stroke allows for comfortable and controllable hand speed, which allows for more needles to be in the needle group, you’ll see that the more needles, at least up to a certain point, equates to a higher saturation rate per stroke. Which means less skin damage and more artistic progress with the least amount of discomfort and effort.

There is however, a maximum amount of needles that preform well in the skin. I don’t describe any needle groups here that are wider than fifteen needles wide, except to say, that through my own research and practical experience, it seems that there becomes a point where, depending on the skin tension and fat content, the skin will bow away from the needle points when the needle group width exceeds a certain amount, (around twenty needles wide). Wide but thin groups of needles, like 45 mags, take more effort to prevent holidays than is worth the coverage. But I do know, you can get workable results with any needle group that you spend the time to master, regardless of what this theory implies.

here are many reasons that fifteen needles wide by five needles deep, is the largest size of needle group that I feel works well in the skin. But the main reasons are;
The skin doesn’t bow away from the needles when the needles hit the skin, not even when the skin is not being stretched. This is the main reason for only fifteen needles wide.
When you hold the machine in the typical fashion, the angle of the needles going into the skin is such, that by the time you push the first row of needles into the skin to the right depth, the fifth row of needles touches the skin very lightly, or maybe not at all. But this is isn’t a problem at all, in fact this actually presents another shading technique that allows you to shade very solid and/or very lightly and very smooth across a large area without leaving needle tracks (skip shade marks).
You can move your hand slow to avoid skip shade marks, but at the same time cover large areas quickly.
And last but not least, (15 x 5) 75 needles is the largest amount of needles that will pass through the ID of a common 5/16 in tube. It just happens to be a coincidence that these three reasons work well, and have become state of the art tattoo techniques.

Lets talk for a minute about how needles marks should overlap when forming a line. Generally speaking, stroke to stroke, both round and flat needle groups should overlap approximately 30% to
50%.
Lets assume we are using the constants we set a moment ago, and that these measurements and speeds are producing a good solid three needle line. Lets apply these same constants to all of the other needle groups, and then compare the results.

If you make a single needle line with the same constants and movements you do with a three needle liner, the results will be slightly different. Because the overall size of the single needle isn’t as big as the overall size of the three needle group. A thinner and weaker line will be the results because a single needle doesn’t over lap the same as 3 needle does. Which may or may not be your intended results.
As mentioned before, stroke length and /or hand speed are the two factors that regulate the spacing of the needle marks. The combination of hand speed and stroke speed becomes the main factor that regulates saturation per stroke, per line, or technique.

If the machine is tuned for a 3 needle group or larger, but you’re using a single needle, and you’re moving your hand speed at the proper rate for your 3 needle lining techniques, increasing stroke speed, in other words, shortening the distance between center to center of the needle marks by shortening the stroke length, you will increase stroke speed. Which would bring the center of the needle marks closer together, while keeping your hand speed constant. This would be the” formula” method to get the (single) needle marks to overlap at the proper spacing.
But, because a single needle liner is so close in size to a 3 needle liner, shortening the stroke, in this case, is not the best option to getting the needle tracks closer together. In order to get a proper line with a single needle, under these conditions, you would or should slow your hand speed down approximately 50%. Adjusting hand speed, along with firm skin tension is probably the best way to get a good single needle line when using a machine tuned as a (3 needle) liner. This is the artistic method.

It’s easy to see that moving the 14 rd needle group with the same stroke length and hand speed as you do for the single needle example, the needle marks overlap more than 95%. This piling up of needle tracks causes blown out lines, over works the skin and causes other healing problems. In this case, slow hand speed actually causes some damage to the skin and line work. But, if you compensate by Increasing your hand speed to separate the 14 needle tracks from a 95% overlap to a 50% overlap, instead of lengthening the stroke. It may work fine for some light lines or minor detail. But, If you increase your hand speed too much, the needle points will rake the skin causing slight skin damage, and choppy ink tracks. You also risk losing control of the needle points. The faster you move your hand the less you can control where the ink goes and how much gets there. Tattooing is the art of patience and finesse. Every mark you in put in the skin, good or bad, is put there by your actions.
To gain control of larger needle groups, simply lengthen the stroke a little bit at a time until you can move your hand at a good pace, but not too fast. Slower hand speed and slow (long) stroked 0.140 to 0.150 (or more) of an inch stroked machines tend to give smoother results, for both lines and shading. But, just like everything else, there is a maximum amount of stroke length that is practical for tattooing comfortably, and for getting good fast results. You’ll know when the stroke is longer than necessary when the distance between skip shade marks becomes too great to manage for the technical effect desired, the size of needle group being used, and comfortable and controllable hand speed. Misuse of a long stroke can easily result in under or over saturated, and over tattooed skin.
Some techniques require a faster stroked machine, long stroke certainly isn’t the answer to every situation or everybody’s hand. But, adjusting hand speed on the fly (and we’re all doing it ) produces better results, and is easier to do when the machine isn’t running faster (shorter stroked) than the skin can accept the lateral moment of the needles without tearing the skin. Speeding up the machine so you can move your hand faster certainly works to some degree, if your intention is to do basic traditional style shading. But if you’re trying to do any serious color blends or transparent effects, it is much easier if you slow down both your hand speed and machine speed.
Almost everyone I’ve helped get into tattooing tend to move their hand in time with the sound of the machine. This is a very hard habit to break. If you have this habit, and your machine is running too fast (short stroked), and you’re using too small of a group of needles, you’ll tend to rake the skin with the needles many times before getting any substantial results. Raking the skin with small groups of needles causes many different saturation and healing problems. Fast hand speed and or stroke speed, actually retards artistic growth, and severely limits the technical effects possible.

Longer stroke and higher power (17-19 volts) allows you to see a longer view of the needle point. This longer stroke length provides you the extra time it takes to work off of the needle points when applying fine detail with all groups of needles. Longer stroke with low power (16-18 volts) gives you the ability to layer pure color over pure color without over tattooing the skin. (a great way to blend colors in the skin is to use the natural skip shading effect, to give the next layer of pure color a place to lay. )
Rounds will overlap the same amount in any direction they’re moved. But flats, which are actually rectangles have two different directions they can be moved. Forward-backward, and sideways. Forward and backwards moves the needles perpendicular to the width of the needles. In other words, if you’re using a 75 needle superflat, which is 15 needles wide X 5 needles deep, and you move them in the direction that the leading row of needles has fifteen needles, you’re moving the needles in a forward or backward direction. If you’re moving the same needle group so the five needle side is leading the way, you’re moving the needle group sideways.
When moving flats, of any thickness sideways, in order to prevent over-tattooing you would tend to move your hand even faster, (but this is not recommended), or slow down the stroke speed by lengthening the stroke, which is recommended.. (If you move your superflats ((or magnum)) needle groups sideways, more than back and forth, you can avoid most skip shading marks, even with a long stroke machine).
If you slow your hand speed to a controllable pace, and lengthen (slow down) the stroke length to the proper length for hand speed and needle group (width) size, you can use very large groups of needles without causing skin damage or overdosing the skin with pigment. But beware, if you have everything working right, superflat needle groups will put pigment into the skin faster than any other groups of needles will.
When tuning a machine I recommend determining the width of needle group this machine will run most often, and set the stroke (length) speed to accommodate that width. If you understand skip shading, you can see why setting the stroke length according to the width of the needle is more practical than setting the stroke to the thickness of the needle group.

If you set the stroke to a 30% overlap according to the thickness of the group, and then move the needles sideways, the overlap would exceed 30%, it would become more like a 90% overlap. This much overlap may, or may not, cause some over tattooing of the skin, or over saturation per technique, you can however, carefully tattoo with this much overlap, but when you do, you should be shading very solid and moving right along with the progress of the tattoo. You don’t have any time to waste here. And remember, the shorter the stroke length, the more you need to be concerned about high hand speed and over tattooing.
I don’t know that I can tell you how much increase in hand speed is permissible, but a little increase is appropriate at times. But if you have to double your hand speed to prevent overdose spots, you would probably benefit from an increase in stroke length. Lengthening the stroke will slow your hand down.
If you don’t change the stroke length, but choose to use larger needle groups than the machine was tuned to use, the needle overlap will increase in proportion to the increase in size of needle group. And there becomes a point where the size of needle group becomes too large, and hand speed becomes too fast for the stroke length, and skin damages begins to occur.

If the stroke is set to allow a 70% overlap according to the width of the needle group, and then you choose to move the needles frontward or backward you may have some skip shade marks develop. This may or may not be what you want, but you can easily control the situation and slow your hand speed down and move the needle more sideways than front to rear.
As I’ve said before, It is much more comfortable and controllable to slow hand speed down, develop a cross hatch technique, and work with large groups of needles, rather than decrease the number of needles and increase hand speed. When you know your tools, you’ll be able to get the job done as quickly as is possible, with the least amount of discomfort and effort.

When you are actually “shading-in” a tattoo, as you move from one stroke to the next, your hand speed will/should be increasing and decreasing instantaneously, depending on the angle of hand stroke, and technical effect being applied. When you’re moving your hand at the proper speed per effect, this change in hand speed and angle of stroke is happening, and happening very fast, on every stroke of your hand. This motion becomes instinctual after enough practical experience.
It is the combination of stroke length, needle group size, shape, hand speed, and skin tension (stretch) that creates the different shading effects of different needle groups. A slight difference in one or more of these details, and you’ll get an entirely different effect.
Tattooing is like playing music. When your instrument is properly tuned, as your needles stroke the skin, if every thing is in tune including the touch of your hand, the color, like a tone, will be pure and clean, you can instantly tell you hit the mark well.
An out of tuned tattoo machine is very much like a guitar slightly out of tune. You may be able to recognize a song being played on it, but you also know it isn’t as good as is possible. A tattoo machine that’s slightly out of tune for the desired effect, or size of needle group, will prevent you from ever hitting the high mark of pure color with no detectable skin damage.

Controlling all the effects possible is the art of tattooing. Controlling your machine’s function, and knowing how to make the mechanical changes necessary to get the artistic effect desired is based in your experience as a craftsman. The quality of your craftsmanship comes first, and for the rest of your career it goes hand in hand with whatever success you experience as an artist. You have to be a good craftsman before mastering the art of tattooing.
Your personal understanding of stroke length and spring tension is the only thing about the electromagnetic tattoo machine that has not already been figured out for you. It is up to you, as a craftsman to learn all you can, but especially learn to control the things you can change. Stroke length hand speed, spring tension, skin tension and electrical voltage are the only things that you can control. Everything else is set by fixed scientific limits.

This is where my stroke theory turns more to a technical effect theory. Both theories seem to go hand in hand, and one theory can not be understood without at least a basic understanding of the other. And these are a few of the tips that I think can put you ahead of the competition if they don’t have a good understanding of stroke and spring function.
It is the artistic effects desired and knowledge of the machine’s ability, not necessarily the machine setup (tune-up), that makes one machine a better liner, and another machine a better shader on any given day. In other words, a long stroked shader machine may give you the needle tip control you need to do fine line script lettering with a lining needle. (turn-up the power a little, and work off of the needle tips).
And you may use a shorter stroked liner machine to do hard and fast coloring of a solid fill area with a superflat, a flat or a magnum needle group. Use the machine and needle combination that does what you need at the time. (The difference between a shader and a liner machine may be no more than .025 to .050 of an inch in stroke length. It’s your choice).
And remember, for the comfort of your client and the advancement of the tattoo, you should install the pigment into the skin as fast as possible. Not by over powering the skin with fast hand pressure and machine speed, but with the right tools for the job and a delicate touch with the largest number of needles that will comfortably fit into the majority of the spaces to be tattooed. The needles should pass over the skin, with the touch of a feather and the force of a kiss, as few times as possible to produce the desired effects.
If there is anything from the ancient art of hand powered tattooing that should influence the next generation masters. It should be the force applied to the needles as they are pushed into the skin, the speed of the needles as they move in and out of the skin and how fast the lateral movement of needles is and how big the needle group sizes used are per technique, and of course the saturation level. Understanding that the needles should go into and be removed from the skin before being moved sideways, like hand powered needles do, is paramount to becoming a Master Tattoo Artist. It is this type of common sense that is now setting the standards and influencing the profession’s future, and the fine art possible with our state of the art tattool equipment. Long stroke, slow hand, good results.
It’s easy to see how round needle groups track in a narrow line with a 30-80% overlap, it is also easy to see how a true flat can track in a fine line with a 30-80% stroke overlap. But when you turn a magnum on its side and draw a line with that same stroke overlap, what you get is a mess.
( I will admit, moving a magnum sideways more often than moving it forward or backward, with proper hand speed and stroke overlap, magnums can produce nice shading results with minimal holidays and out of place skip shade marks).
One of the problems with magnums lie with the spread and separation of the needles. With a magnum needle group, even the 30-80 % overlap rule is not enough for the needles to saturate the skin without many passes. In fact, with Magnums, it isn’t the stroke overlap that saturates the skin, it is the increased number of passes required of the needle group that eventually saturates the skin. By nature’s design, “Magnum” style needle groups are designed to dilute the saturation of pigment, not increase it.

But, (and this is the second biggest but in the industry). There are now better tools for getting soft shading, than by diluting the needle tracks through reducing and separating the number of needles in the group.The name “Magnum needles” is an oxymoron, much like the term temporary tattoo” . Magnum style needles do not install pigment in the magnum (largest) amount with the least amount of effort. On the contrary, Magnums install pigment, in the least amount with the most effort, you must rake the skin many times in order to saturate the skin. The more you rake the skin with needles, the greater the risk that skin (and needle) damage is being done.
Magnum needle groups should not be used to shade solid. In all reality, Magnum needle groups should only be used for a very limited time and effect, if at all. It’s time for Magnums to replace Flats, on the shelf of obscurity.
You wouldn’t know it by their reputation but true Flats (and our Superflats) are, by natures design, able to saturate the skin with pigment much faster and better than magnums. Superflats offer a better finish, they are more versatile, and require less effort than magnums.
Superflat needle groups are not the same as Magnum needle groups, they do in fact saturate the skin in the maximum amount with the least amount of effort, or trauma to the skin. And therefore you will need to practice with them for a little while before you get an understanding of how they feel in the skin. If you work with superflats for thirty to forty hours, with the right stroke length and power (voltage) setting, I don’t think you’ll ever go back to mags. And your clients will appreciate the change in pain sensation, healing time and the other benefits that come with using superflats.

Because of the difficulty in tuning fixed spring machines, and the disadvantage small needle groups impose, most tattooers I know have inadvertently taught themselves to think simple artistic thoughts. And because of that, artistically speaking, they don’t have to plan very far ahead of what they are currently doing, because their tools won’t let them work any faster. Although most tattooers try to work faster by moving their hand faster. Good tattooing does not work that way.
You can only get so much done in a comfortable setting. It’s common sense that you would want to use as large of a group of needles as possible. Superflats are so much faster than magnums at putting pigment into the skin, you really do need to know where you’re going, artistically speaking, in order to handle them most efficiently.

(And this is where the techniques described here will open the doors to your imagination. When you can paint bigger areas faster with more complete details than you can with magnum needles, your imagination ((and income) ) has room to grow. And if you grow, so will the profession.)

Short stroked, fast acting, machines and fast hand speed are never a good combination, that is if you care about the results. If you think your tattoo results are under detailed and over tattooed, they probably are. If your machines are tuned to be short stroked fast acting machines you will find that certain types of detail shading is not even possible. But, you’ll never know what type of shading is possible unless you learn enough about stroke techniques to know what does work for you. Until you know what doesn’t won’t work for you, you don’t know they won’t work.

If you can “see” your art but can’t get the results you think are possible, my bet is that you just need to find a longer stroke, and bigger group of needles where appropriate. Then slow down your hand speed, be patient and follow your imagination.

Slowing your hand speed down will definitely correct some detailing and healing problems, but won’t solve every problem. In fact, as we all know, long slow strokes and even moderate hand speed can produce an undesirable “skip” shading effect. (Moving your hand faster to fill in the skip shaded areas can work to some degree, but not as a style of tattooing, but as a technique that should be of limited use.) Skip shading effects are not seen, naturally, in any other art medium, it is a technique unique to tattooing and should be used only when appropriate. When viewed by most tattooers, the effects of skip shading is a sign of lack of care, control and/or experience by the tattooer that did the work in question.
But there are however, a few circumstances, where controlling and therefore putting skip shading effects in the right places, is one of the few indicators of the total control of a Master Tattoo Artist. If you can place skip shading effects in the design in a manner that compliments the actual effect and design, you’ll be well on your way to reaching your potential to master this art form. Skip shading is not a technique to be shunned or ignored, but a technique that needs to be mastered if you want to master this medium.
And this is where the art of tattooing comes into play. Hand control is the most important aspect of tattooing. If you can work at the speed where your eye and hands controls the results, rather than the machine controlling your hand speed, your immediate imagination can have a bigger influence on the final results. That is, if you know your tools, and how to lay the shading (or lining) effects that they’re capable of.

Of course, cross hatch shading with the same color will blend unwanted skip shading effects smooth. If you cross blend those skip shading effects with another pure color you can get very nice color blends, with or without texture. Some color blends and textures are not possible when you pre-mix the pigment in the cup or on the needle. Blending pure colors under the skin is not possible if there is not any room for the color to stay pure. Skip shaded areas provide the untainted space for the next color to lay.

Long soft strokes with large needle groups allow you to pass over the same area many times before skin damage begins to occur. This will give you the ability to turn down the power (but not too low) and rework holidays or blend colors, without over tattooing the surrounding skin. And this is what it takes to get smooth solid shading on the first sitting. But, sometimes it takes another sitting to get the blend of color(s) you want, or the blends or textures that are possible.
When you intentionally create vacations (intentional holidays) and leave skip shaded areas open, later, in the same setting or a sitting in the future, you can blend another layer of pure color into though areas left open, and now you have layered effects of pure color.
Here’s a little exercise to help you get familiar with the technique of color blending. Skip shade several colors across a large area, or maybe several adjoining areas of the same design, or maybe all of the areas facing toward or away from a light source. And then blend the skip shaded area smooth with the predominate color that controls the light source. You blend the color(s) until the skin is saturated with the color that appeals to your eye and compliments the piece. Let it heal for a few weeks and blend smooth again if necessary.

Most often, it is impossible to get all of the pigment into the skin on the first application, that the skin can actually hold. Sometimes you get all of the pigment you need in the skin on the first setting, and that is good. But even small single setting tattoos most often look better and hold-up better over time when some colors are worked into the skin a second time, as soon after the first time that healing permits, (before the Epidermis heals). Usually three or four weeks is sufficient healing time, before working over the tattoo with another layer of color, without worry of over tattooing the skin.
Saturation is the key to getting solid, smooth and brilliant color, including color blends that cover large areas. Saturate, saturate, saturate, but do it gently, as many times as it takes. For best and quickest results, use the largest group of needles that will fit comfortably into the majority of the areas between the lines of the design. And use all of the power (voltage and spring tension) you need, but only enough to get the job done.
Of course this isn’t all there is to understanding stroke and needle effects, but this information should give you something good to think about. I think I’ve covered a little bit of most every aspect of stroke length theory, at least in some small way. Once you understand this theory, you will be able to fill in the gaps of information with your own techniques. And that is what I hope will happen. I hope I’ve given you some good positive information that will help you, and our profession grow.
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