How to coat a Mesh with Emulsion

Set Up Your Workspace

Before coating, make sure your environment works with you — not against you.

Use a UV-Safe Room

Emulsion reacts to UV light. Even weak, indirect daylight can start the exposure process too early.
Use:

• A proper darkroom
• Yellow or red safe lights
• No windows / covered windows

Prepare Your Tools

You’ll need:

• Emulsion (freshly mixed; let it sit so air bubbles escape)
• Scoop coater (one sharp edge, one round edge is ideal)
• A clean frame with mesh (minimum tension: 20 N)

And one crucial rule:

👉 Your mesh must be absolutely clean — no dust, no oil, no fingerprints.
Contamination = pinholes.

The Basic Coating

The goal of coating is to achieve proper EOM (Emulsion Over Mesh) — the emulsion layer sitting ABOVE the mesh threads. Too thin = ink bleed. Too thick = loss of detail.

Here’s the correct basic method:

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Step 1: Coat the Print Side (Shirt Side)

1. Load your scoop coater (about ⅔ full).
2. Hold the screen vertically.
3. Tilt the coater until the emulsion touches the mesh.
4. Pull upward slowly with steady pressure.

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Step 2: Coat the Squeegee Side

Flip the screen.

• Apply one coat on the squeegee side.
• This pushes emulsion into the mesh and starts building the correct gasket layer.

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Step 3: Dry the Screen Properly

Dry print side down on a flat surface.
This allows gravity to pull the thickest layer toward the shirt side — where it belongs.

Drying Environment Checklist

• Dust-free
• Warm but not hot
• No airflow directly hitting the mesh
• No UV light

A well-dried screen = consistent exposure + fewer pinholes.

Why Do the Surface Coat?

The surface coat is an extra pass that changes everything.

What the Surface Coat Does

• Adds extra emulsion thickness where needed
• Improves EOM for durability
• Fills thin spots and micro pinholes
• Creates a smooth surface for sharp edges and gradients
• Ensures a consistent stencil thickness

If you want crisp halftones, solid whites, and long-run durability — the surface coat is essential.

The Basic Coating with Surface Coating

Below is the most reliable method used in professional shops.

1. Coat the Print Side — First

2. Coat the Squeegee Side — Second

3. Dry Print Side Down

4. Apply a Surface Coat to the Print Side

5. Dry Print Side Up

Video: How to Coat a Mesh

Here’s a short 1-minute demonstration:

Coating a Screen Printing Mesh with Emulsion – Screen Printing in One Minute

Questions & Answers

What happens if I apply too much emulsion?

You can scrape off the excess using the sharp edge of your scoop coater. Remove from both sides and start the coating process again.

Why do I see fisheyes or crater defects?

This is caused by contamination, usually from:

Why do I see bubbles or pinholes after drying?

You coated too quickly.
Mesh needs time to fill with emulsion — speed traps air inside, creating bubbles.

👉 Slow down your coating stroke.

Why does emulsion drip during drying?

Because you applied too much emulsion or used the wrong coater edge for your mesh count.

Pro Tips to Improve Your Coating Quality

• Coat slow — speed causes bubbles and streaks
• Keep the coater edges clean — scratches leave lines
• Use the round edge for low mesh counts (more emulsion)
• Use the sharp edge for high mesh counts (less emulsion)
• Always dry horizontally — never upright
• Check for even shine — a good indicator of proper EOM

Conclusion: Coat Smart, Print Brilliantly

Coating the mesh with emulsion is the foundation of every great screen print. Mastering this step ensures:

• Sharp details
• Strong stencils
• Fewer pinholes
• Better ink control
• Longer durability

Take your time, keep your environment clean, and apply consistent technique. With practice, your coating will become predictable, repeatable, and professional — ready for any print job.