Depth of Penetration
How deep into the skin do you deposit the pigment? Not very deep.
Lets start with the needle. A common tattoo needle is .0125 in diameter. That is twelve and one half thousandth of an inch in diameter. The taper can be any one of several different angles that work well for tattooing, you can use different tapers for different reasons.
Most pigment, now a days, is ground very fine. A long taper needle will deposit fine grain pigment deeper into the skin with less risk of skin damage. Long tapered needles work well for total saturation and they also help feather pigment into the skin for softer smoother effects, like transparent layering. The smooth finish of long taper stainless steel needles, is better when preground pigment is used.They are not as hard on the skin and they’re a little more versatile than short tapered ground round needles.
Short tapered needles work best with large grain pigment. Because a short tapered needle will open the hole in the skin cell faster, large grain pigment, or large amounts of pigment can be pushed into the cell per stroke, in a short amount of time. For some skin types short taper needles will shade very solid very fast. But they won’t shade to a fade very easy. The shorter the taper, the greater the risk that you will push the needles a few thousandths of an inch too deep into the dermis cells, and the outer most cells of the dermis will tear, causing scar tissue.
Short tapered needles are best when used with dry mixed pigment. Because dry pigment hasn’t been ground very fine it requires a larger hole in the cell to deposit the bigger chunks of pigment. “Ground round” steel needles cause minor skin damage, they should no longer be used. But if they are used, they’re best when used with dry mixed pigment.
Heres how you know how deep to go.
As the needle penetrates into the Epidermis, the skin cells that the needle points penetrate into, in a sense, slide up the taper of the needle. There becomes a point where the skin cell can not stretch any more as the taper of the needle is pushed into the skin, and the cell tears. As you’re tattooing look at the surface of the skin, as you near the saturation point the absolute surface of the - epidermis - skin will become ruptured and take on a look and texture similar to brushed velvet. If you pay close attention to this brushed velvet look, you can use it as an indicator of saturation of the pigment. Or, an interruption in texture can indicate a holiday of pigment, a holiday that you may not see otherwise until healed. This brushed velvet look is the results of pushing the needles into the Epidermis skin cells beyound their ability to stretch over the diameter of the needle. You don’t want the cells of the Dermis to look like that, ever.
As the needle point passes through the epidermis and enters the Dermis ideally you want the needle to poke a hole into the outer skin cell of the dermis, and continue being pushed into the underlying cells until the taper of the needle is pushed into the first dermis skin cell until the cell has expanded almost to the point of tearing. And the needle is then pulled from the skin before the cell tears. If you only allow the needle to penetrate until the first skin cell of the dermis is stretched to the maximum without bursting, and you saturate the surrounding skin to the same degree you won’t have any scarring, and the pigment of a healed tattoo will be most brilliant.