Understanding Tattoo Needle Depth | PainfulPleasures (2024)

Figuring out the right needle depth can be intimidating. Too deep and you cause blowouts and extra pain for your client. Too shallow, and the tattoo will fade in a matter of weeks. Either way, the client won’t be happy. Pretty high stakes, right?

So how the hell do you know you’ve got the needle depth right if you’re new to putting needles to skin? As always, we’re here to help, covering everything you need to know—from stroke length to skin layers.

What is Tattoo Needle Depth?

First, let’s make sure we’ve all got the correct definition of tattoo needle depth. Basic as it sounds, there’s often some confusion here for newer artists. Simply put, needle depth refers to how far your tattoo needles stick out of your tube or cartridge tip, which of course, determines how deep they’ll go into the client’s skin.

Make sure not to confuse stroke length with needle depth. While stroke length can play a role in needle depth, those numbers refer to different measurements (more on that below)

How Does a Tattoo Machine Work?

Before we dive into the layers of skin (no pun intended), it’s helpful to have a basic understanding of how your machine works. For now, we’re just focusing on how the needles move and the relationship between stroke length and needle depth. (For a more in-depth explanation, check out our comparison of Coil Machines vs Rotary Machines and our breakdown of How Coil Tattoo Machine Springs Work).

Your machine uses either springs and electromagnetic currents (coil machines) or a rotary motor (rotary machines) to move your needles. The currents or rotary motor quickly drive needles up into the cartridge or tube to collect ink, then down past the tip of the cartridge to penetrate your client’s skin.

About Stroke Length

For coil machines, stroke length is the distance the armature bar travels before it strikes your needle. For rotary machines, stroke length is the amount of travel your cam wheel (or stroke wheel) makes around its bearing in one rotation. In other words, stroke length is the combination of how far your needles stick out from the cartridge tip plus how far they must travel back into the tip.

The longer your needle depth is, the longer your stroke length must be. Why? If you set a long needle depth but a short stroke, your needles won’t be able to retract far enough to pick up more tattoo ink. This makes for patchy tattoos and the potential that your needles will hang out of the machine even when it’s off. This creates potential for dangerous accidental needle sticks.

Understanding Skin: How Deep is the Dermis

Let’s peel back the layers (like, metaphorically) and cover the basics of skin anatomy. The skin has three main layers: the epidermis, the dermis, and the subcutaneous layer.

The epidermis is the visible top layer of the skin. It varies in thickness depending on the location on the body, from its thinnest at .05mm on the eyelids to its thickest at around 1.5mm on the palms and soles. Inmost areas that you’ll be tattooing, the epidermis’s thickness falls somewhere between those two extremes. This layer constantly regenerates, meaning that ink deposited here won’t stay for long.

Below the epidermis is the dermis, the sweet spot for tattoo needle ink. This layer has rigid cells, perfect for holding ink exactly in place. This is the thickest layer of the skin. It usually extends 1 to 2mm below the surface of the skin.

Below the dermis is the subcutaneous layer, a fatty layer with plenty of blood vessels. You don’t want your needles to extend to the subcutaneous layer. For one thing, hitting this layer creates a lot of unnecessary pain and bleeding for your client. For another, the cells in this layer aren’t rigid enough to hold the ink in place as they are in the dermis. This means the ink spreads out, creating a blowout. The pain may be temporary, but the sloppy look of a blowout isn’t, and your client will need extra work to cover it up.

How Far Does the Tattoo Needle Need to Go?

Where Should the Tattoo Needle Go?

Again, you want your needles to reach the dermis and no farther. This usually means the needle should penetrate about 1–2mm (usually a bit closer to 2) or around 1/16th of an inch into the skin. When the needle exits the dermis, it will create a seal or vacuum. This seal traps the ink in place within the rigid cells of the dermis.

How Do You Set Your Needle Depth?

There are two basic methods you can use to make sure you’re hitting the right needle depth.

Method 1: “Riding the Tube”

This is usually the best method for beginners. In this case, as you set up your machines, you’ll make sure the needles extend no more than 2mm past the tip of the cartridge or tube. This way, it’s nearly impossible to penetrate too deep and hit the subcutaneous layer.

But because your needles are extending 2mm max past the tube, you’ll need to touch the tube to the client’s skin as you work to make sure you penetrate past the epidermis into the dermis. The main disadvantage to this method is that it makes your stencil tougher to see. You’re more likely to smudge it or get ink on it.

Method 2: “Floating the Needle”

Just like it sounds, in this method, you float or hover the tip of the machine just slightly over the surface of your client’s skin, about a millimeter or so. The tube doesn’t contact the skin, making it easier to keep the stencil clean and visible.

You’ll need to set your needle depth and stroke length to make up for the extra millimeter or so of space. Because the needle will extend farther than 2mm from the tip of the cartridge or tube, you’ll need to be careful to maintain a consistent distance. If you close that distance, you can cause blowouts.

What if The Tattoo Needle Is Too Shallow? Too Deep?

A needle depth that’s too shallow only hits the epidermis. Because the cells in this layer constantly regenerate, the ink won’t last long, and the tattoo will look worn and faded in a matter of weeks. Go too deep, and you’ll notice that the ink appears to spread slightly under the skin. Consequently, your client may bleed more or express more discomfort.

The Importance of the Stretching Hand

The hand you use to stretch the skin as you tattoo helps provide critical sensory feedback, letting you know whether you’ve got the right needle depth. When you hit the dermis, you’ll feel a slight vibration in the stretching hand. You’ll also feel just the slightest “tug” as the needle exits the dermis and creates the “vacuum seal.” Reminder: the vacuum seal holds the ink in place within the dermis.

This sensory feedback is something you’ll have to experience to truly understand. So, in the early stages of your career as you “ride the tube,” make sure to pay attention to the sensations in the stretching hand. The more practice you get, the more you’ll fine-tune your sense of depth. Soon, you’ll be able to trust your senses. Then you can float the needle and still feel confident about your needle depth.

Final Thoughts on Tattoo Needle Depth

Getting your needle depth right may feel scary as hell at first. After all, the quality of your work and your reputation as an artist depend on it. But don’t let it freak you out. In the early days, you’ll depend on the “riding the tube” method, setting your needles and stroke length so that they extend a maximum of 2mm past the tip of the cartridge or tube. Before long, you’ll gain that sixth sense for needle depth. Eventually, you’ll learn to trust your stretching hand (and your gut), so choosing the right needle depth becomes second nature.