Advanced Screen Printing Vocabulary: A Technical Language Lesson

Advanced Screen Printing Vocabulary: A Technical Language Lesson

Screen printing borrows a lot of language from other industries — chemistry, engineering, geology, photography — which can make technical conversations sound like a foreign language to printers who are newer to the craft. Below are some of my favorite terms from the screen-printing lexicon. While there are hundreds more I could include, these are the words I find myself explaining most often.

Understanding these terms doesn’t just make you sound smarter — it helps you diagnose problems faster and communicate more clearly on the shop floor.

Artifacts

Artifacts are any unintended visual defects that appear in a print but are not part of the original artwork. They can show up as patterns, textures, lines, dots, or distortions and are usually the result of interactions between the artwork, the screen, the ink, and the printing process itself.

Common artifacts include moiré patterns, jagged edges, sawtoothing in halftones, pinholes, banding, ghosting, and uneven ink deposits. Artifacts are not ink failures — they are process failures, typically caused by incorrect mesh selection, poor screen tension, improper halftone setup, incorrect exposure, excessive squeegee pressure, or inconsistent press setup.

Base

This is like the word “that” in that that word has various uses, so it causes a lot of confusion because it has multiple meanings depending on context.

• Underbase: The first-down ink layer used to knock down fibers and create a foundation for opacity or color accuracy.
• Ink base: A carrier component in an ink system used to hold pigments or special-effect media like glitter or metallic flake.
• Additive base: A product used to modify ink properties such as viscosity or hand feel.

Whenever someone says “base,” you need to ask which base they’re talking about.

Boogers

Boogers are bits of lint or foreign debris that get trapped in the mesh during printing and interfere with the image. In the Midwest, these are often called “Nerds” — because apparently people there are too classy to use the word booger.

Conveyor Dryer

No need to define this one — but depending on where you are, you may hear it called a heater, cooker, oven, gas tunnel, belt dryer, cure tunnel, curing unit, IR tunnel, electric dryer, gas dryer, or even a pizza oven.

Side note: if you have a quartz dryer, do not reheat your pizza in it. The oils coat the quartz bulbs and cause problems down the road.

Deflection

Deflection refers to the temporary bending or displacement of materials under force during printing. It most commonly applies to the mesh, squeegee, and garment.

• Mesh deflection: How much the screen bends during the print stroke. Excessive deflection causes blurred edges and registration issues.
• Squeegee deflection: Blade flex under pressure. Controlled deflection helps shear ink; too much smears detail.
• Garment deflection: Fabric compression during printing. Excessive deflection allows fibers to rebound through the ink, causing fibrillation.

Controlling deflection is critical for clean ink transfer and consistent results.

Durometer

Durometer measures the hardness of flexible materials like rubber and polyurethane. In screen printing, it refers to squeegee blade hardness and directly affects ink deposit and detail.

Durometer is measured on the Shore scale, usually Shore A.

And if you already knew this term, there’s a good chance you learned it from Tony Palmer, like I did.

E.O.M. (Emulsion Over Mesh)

E.O.M. describes the percentage of emulsion thickness relative to the mesh. It’s a key factor in ink deposit, especially for specialty inks like white ink, metallics, puff, and high-density prints.

Flash Unit

A flash unit gels ink so another layer can be printed on top. It is not designed to fully cure ink.

Other names you’ll hear:

Flasher, heater, flash dryer, lamp, IR panel, heat panel, hover dryer, spot dryer, heat head, burn box, gel unit, or dry station.

Fibrillation

Fibrillation is when fabric fibers are pulled up through the ink film, creating a fuzzy or rough print surface. It’s typically caused by excessive pressure that compresses the garment and allows fibers to rebound through the ink. This can also occur when too low of a mesh count is used on looser knits.

Ink

If you call it “paint,” we are all going to point and laugh at you.

Intercoat Adhesion

Intercoat adhesion is the ability of one ink layer to properly bond to a previous ink layer. It depends on flashing the first layer enough to gel — but not fully cure — so the layers fuse together. Poor intercoat adhesion leads to peeling, cracking, or delamination.

LPI (Lines Per Inch)

LPI measures halftone detail.

• 25–35 LPI: Coarse, easy to print
• 40–50 LPI: Balanced detail
• 55+ LPI: Fine detail, higher risk of moiré

LPI must match mesh count.

Rule of thumb:

Mesh ÷ 4 ≈ max LPI

(156 mesh ≈ 35–40 LPI, 230 mesh ≈ 50–55 LPI)

Moiré

Moiré is an unwanted wavy or rippling pattern that appears in the print when halftone dots interfere with the screen mesh. It occurs when dot frequency or angle is too close to the mesh count or weave.

The fix is not more pressure or ink. It is geometry.

Change angles (consider using 22.5°, 45°, or 67.5°), match LPI correctly (mesh ÷ 4 ≈ max LPI), increase mesh tension, or slightly rotate the artwork (2–5°) to break alignment.

Recovery

Recovery describes a material’s ability to return to its original state after being stretched, compressed, or sheared.

• Mesh recovery: Snap-back after deflection
• Garment recovery: Fabric rebound after compression
• Ink recovery: Ink returning to proper viscosity after shear

Strong recovery across all three is essential for consistent printing.

Shear

Shear is the force created when layers of material slide past one another. In screen printing, shear occurs when the squeegee or flood bar moves ink through the mesh.

Shear reduces viscosity, allows ink to flow, and then lets it recover once motion stops.

Too little shear causes uneven deposits. Too much destabilizes ink.

When we are pre-shearing ink, we are not mixing it. We are cutting, folding, and stirring the ink.

Shore

Shore refers to the hardness scale used for elastomeric materials. In screen printing, it quantifies squeegee hardness, usually on the Shore A scale.

Lower Shore = more flex and heavier ink deposit.

Higher Shore = less flex and sharper detail.

Stratigraphy

Borrowed from geology, stratigraphy describes layers within a structure like a cliff profile. In screen printing, it refers to visible layers of ink stacked on top of each other.

If a high-density print shows obvious layers instead of a uniform profile, you might describe it as “stratified.”

Thixotropic

Thixotropic materials become thinner when agitated or sheared and thicken again at rest.

Inks with good thixotropy flow easily during printing, then hold their shape on the garment without dripping, slumping, or spreading.

See my previous post called Why Pre-Shearing Your Plastisol Ink Is Essential for Better Prints.

Topography

Another borrowed term, topography describes surface highs and lows. In screen printing, it refers to the surface texture of the ink deposit.

If a puff print fails and looks uneven, you might say the print has poor topography.

Ok, I could go on. But not right now. Impressions is just around the corner and I have to put together a seminar for Impressions Long Beach called Advanced Ink Selection: Balancing Quality, Efficiency and Cost. I hope to see you all there.

And please remember that not everyone loves hugs. A handshake is sufficient.