Terms & Acronyms for Screen Making: Cheat Sheet
Screen Making Terms and Acronyms Cheat Sheet
A plain-English glossary for faster setups, fewer mistakes, and better screens.
If you have ever read a tech sheet, watched a YouTube tutorial, or talked with a supplier and thought, “Wait… what does that mean?”, this post is for you.
Screen making comes with its own language. Some terms describe what you are doing (degreasing, reclaiming). Others describe what went wrong (pinholes, scum). And a lot of acronyms describe equipment or processes (CTS, LTS, DDU).
Bookmark this blog post as a quick reference or print the Screen Making Terms & Acronyms Cheat Sheet pdf and share it with your team.
Quick cheat sheet: the screen making workflow
Most screen problems trace back to one of these stages:
- Art and film (how the image is generated)
- Coating (how the stencil is applied)
- Exposure (how the stencil is hardened)
- Washout and post-exposure (how detail is opened and locked in)
- Reclaim (how the screen is restored for reuse)
--> Download & Print PDF: Screen Making Terms & Acronyms Cheat Sheet
A. Art and prepress terms
Prepress is where quality begins. Clean artwork, correct resolution, and strong film positives help you hold fine detail, keep edges sharp, and reduce “mystery problems” later in exposure and washout.
| Term / Acronym | Definition |
|---|---|
| DPI (dots per inch) | A measure of image resolution in the artwork file. Higher DPI generally supports sharper edges, especially for fine detail. |
| LPI (lines per inch) | How many halftone lines appear per inch. Higher LPI requires tighter control of mesh, exposure, and contact. |
| Halftone | Dots arranged to simulate gradients. Halftones demand consistent coating, accurate exposure, and good contact. |
| Positive (film positive) | The opaque black image that blocks UV light during exposure. “Good positive” usually means dense blacks and clean edges. |
| Film density / Dmax | How well the black areas block UV light. Low density can cause weak stencils and edge issues. |
| Registration | How multiple colors align. Inconsistent stencil thickness, mesh tension, or under/over exposure can affect register. |
| Trap | A small overlap between colors to reduce gaps from registration variation. |
| Moiré | An unwanted pattern caused by interference between mesh angle and halftone angle. Often solved by changing angles or mesh. |
B. Screen and mesh terms
Mesh is your foundation. The wrong mesh count, thread diameter, or tension can make an otherwise “perfect” stencil feel inconsistent on press. Getting these basics aligned makes everything downstream more predictable.
| Term / Acronym | Definition |
|---|---|
| Mesh count | Threads per inch. Higher mesh holds finer detail and deposits less ink. Lower mesh lays down more ink. |
| Thread diameter | Thickness of the thread. Two meshes can share the same count but print differently if the thread diameters differ. |
| Open area (%) | How much “open space” exists in the mesh. More open area generally means more ink flow. |
| Mesh tension (N/cm) | How tight the mesh is stretched. Proper tension supports sharp prints, easier registration, and improved stencil durability. |
| Knot / weave | How the mesh is constructed. This can influence coating behavior, detail, and print consistency. |
| EOM (emulsion over mesh) | How much stencil thickness is built above the mesh on the print side. EOM impacts ink deposit, edge definition, and durability. |
C. Coating and stencil-building terms
Coating is where repeatability is won or lost. Understanding emulsion types, coating method shorthand, and common coating defects helps you build consistent stencils that expose cleanly and hold up on press.
| Term / Acronym | Definition |
|---|---|
| Emulsion | The light-sensitive coating that forms your stencil. |
| Diazo | A sensitizer type commonly used to make dual-cure emulsions. Known for good latitude and durability. |
| Photopolymer (SBQ) | A “ready-to-use” emulsion chemistry (often called SBQ). Typically fast exposure and consistent results when dialed in. |
| Dual-cure | Emulsion chemistry that combines photopolymer properties with diazo sensitizer benefits. Often chosen for durability and latitude. |
| Solids content | How much actual “stencil material” is in the emulsion. Higher solids can help build thickness more efficiently. |
| Viscosity | How thick or “flowy” the emulsion feels. Viscosity affects coating behavior and consistency, but it is not the same as solids. |
| Scoop coater | The coating tool. The edge profile and sharpness impact coat quality and repeatability. |
| 1 over 1, 2 over 1, etc. | Coating method shorthand. Example: “2 over 1” usually means two coats on the print side and one coat on the squeegee side (shops may describe this differently, so confirm how your team uses the terms). |
| Wet-on-wet | Applying multiple coats without fully drying between coats. Can build thickness efficiently, but demands controlled drying. |
| Streaks | Visible lines in the coating. Common causes include poor degreasing, damaged coater edge, contamination, or wrong coating speed. |
| Fish eyes | Small round “craters” where emulsion pulls away. Often caused by oil, silicone, or residue on the mesh. |
| Pinholes | Tiny open spots in the stencil after washout. Often caused by dust, poor degreasing, or bubbles during coating. |
| Drying cabinet / dry box | A controlled environment for drying screens. Consistent drying is one of the biggest factors in consistent exposure. |
D. Exposure terms (where most acronyms show up)
Exposure is where the stencil becomes durable and printable. Most exposure issues come down to light output, time, and contact. These terms will help you diagnose whether you’re dealing with energy, equipment, or process control.
| Term / Acronym | Definition |
|---|---|
| UV (ultraviolet light) | The light that hardens the emulsion. |
| Exposure unit | Equipment that delivers UV light in a consistent way. |
| Lamp type (metal halide, LED, etc.) | Different sources behave differently. The key is consistent output and consistent timing. |
| Contact | How tightly the film/positive is pressed against the emulsion. Better contact equals sharper detail. |
| Vacuum frame | A system that pulls the film tight to the screen during exposure to improve contact. |
| Underexposure | Stencil is too soft or weak. Symptoms include slimy washout, edge breakdown, and short run life. |
| Overexposure | Stencil is too hard to wash out. Symptoms include closed detail, lost halftones, or stubborn “scum.” |
| Exposure latitude | How forgiving an emulsion is when your exposure time is not perfect. |
| Step wedge (exposure calculator) | A tool to dial in exposure. If you want repeatability across shifts and seasons, this is one of your best friends. |
| Post-exposure | Exposing the screen again after washout to further harden the stencil. Often improves durability. |
E. Washout, stencil quality, and troubleshooting terms
Washout is where detail is revealed and problems show up. Knowing the language around stencil defects helps you communicate clearly with your team and narrow down whether the root cause is coating, exposure, film, or reclaim habits.
| Term / Acronym | Definition |
|---|---|
| Washout | Rinsing the unexposed emulsion away to open the image. |
| Scum | A thin film of emulsion that remains in open areas. It can block ink flow and cause printing issues. |
| Haze | A “ghost” image in the mesh after reclaim. Haze is not always visible until you hold the screen to the light. |
| Sawtoothing | Jagged edges on what should be smooth lines. Often linked to mesh selection, film quality, contact, or exposure. |
| Edge definition | How clean the stencil edges are. A major driver of perceived print quality. |
| Stencil durability | How well the stencil survives production. Influenced by emulsion choice, exposure, ink type, and reclaim habits. |
F. Reclaim and chemistry terms
Reclaiming is how you protect screen consistency over time. The right sequence and the right chemistry keep mesh open, reduce ghosting, and help your next stencil adhere and expose more predictably.
| Term / Acronym | Definition |
|---|---|
| Reclaiming | The full process of returning a screen to usable mesh: remove ink, remove emulsion, remove haze, degrease. |
| Ink degradant | Chemistry used to break down ink for easier removal. |
| Emulsion remover (stripper) | Chemistry designed to remove the stencil. |
| Haze remover | Chemistry designed to remove stain and ghost images. |
| Degreaser | Used to remove oils and residue to help emulsion wet out and bond to the mesh. |
| Pressure washer | Common washout and reclaim tool. Used correctly it saves time. Used incorrectly it can drive haze into the mesh or damage it. |
| DDU (drum dispensing unit) | A dispensing system that delivers chemistry consistently and reduces waste. |
G. Equipment acronyms you will hear a lot
These acronyms show up in equipment discussions, demos, and ROI conversations. Understanding them helps you compare workflows and make smarter decisions about consistency, throughput, and labor in the screen room.
| Term / Acronym | Definition |
|---|---|
| CTS (computer-to-screen) | A digital screen-making system that images the stencil directly from a computer, traditionally using inkjet or wax to create the screen’s “positive.” It is then typically exposed with LEDs on the same machine prior to being washed out like normal. |
| LTS (laser-to-screen) | A system that uses lasers to expose the stencil directly from a computer onto a coated screen. It is technically a subset of CTS and is often chosen for speed, high resolution, and low maintenance. |
| Auto coater / automatic coater | A machine that applies emulsion to screens with consistent, uniform thickness at scale, reducing the variation common with hand coating. |
| Exposure calculator | A step-test tool used to confirm correct exposure. |
| RIP (raster image processor) | Software that converts artwork into output for film, CTS, or other imaging systems. |
A few terms that get mixed up (quick clarification)
Some “problem terms” sound similar but point to different root causes. Keeping these distinctions straight can save time when you’re troubleshooting and deciding what to change first.
| Term / Acronym | Definition |
|---|---|
| Solids vs viscosity | Solids is “how much stencil you are building.” Viscosity is “how the emulsion behaves while coating.” They are related, but not the same. |
| Haze vs leftover emulsion | Haze is stain in the mesh. Leftover emulsion is stencil residue. They look similar, but they respond to different chemistry. |
| Underexposure vs poor film contact | Both can cause soft edges and lost detail. One is about time/energy, the other is about contact quality. |
Want help translating this to your shop?
If you want, tell us what inks you print (water-based, plastisol, UV), what mesh ranges you run, and how you expose and reclaim. A knowledgeable Chromaline representative can help you match terminology to a repeatable screen making process, and recommend the right stencil and chemistry setup for your workflow. Contact Chromaline Screen Print Products with any questions.