Screen Printing Troubleshooting Tips

From exposure to washout, we offer a detailed list of common screen printing problems below, along with possible solutions. For a free printable Troubleshooting Guide, click here.

Washout Breakdown—Adhesion Loss During Developing

Check user's guide for coating instructions. Use proper scoop coater.

Use yellow or subdued lighting in screen making area; dry screen in total darkness. Check lot number on packaging.

Follow drying directions. Dehumidifier recommended in drying area.

After coating with transfer emulsion, allow about 10 minutes to elapse (dwell time) before placing screen into dryer or in front of a fan.

Degrease properly with Chroma/Clean. Use wetting agent, such as Chroma/Wet.

90 to 100 degrees F (32 to 38 degrees C) optimum water temperature.

Decrease water pressure and/or time of washout.

Use Chromaline Exposure Calculator to determine proper exposure time and light source performance.

Degrease properly with Chroma/Clean degreaser.

Washout Difficult—During Developing

Check density or image quality; emulsion of positive should be in contact with stencil emulsion.

Use yellow or subdued lighting in screen making area; dry screen in total darkness. Do not use outdated material.

Do not exceed 110°F (43°C). Chromaline recommends 85° to 95°F (30° to 35°C). A dehumidified drying cabinet is best.

Shorten exposure; run an exposure test.

Use dyed or tinted fabrics. Increase exposure time 25 - 100 percent.

Check the quality of your positive; check vacuum frame is in complete contact in all areas of the screen.

Pinholes

Be sure powder is completely dissolved before mixing with emulsion.

Apply additional coats on print side after drying; or use higher solids emulsion.

Check user's guide for correct film thickness and mesh selection.

Allow emulsion to settle a minimum of two hours after sensitizing; allow additional setting time if emulsion is re-blended.

Degrease mesh properly, using Chroma/Clean degreaser.

Use Chromaline Exposure Calculator to determine proper exposure time and light source performance. Feel squeegee side of stencil during wash out. If it feels slimy or you get color on your fingers, screen is underexposed.

Shop cleanliness. Clean artwork, film and vacuum frame glass prior to use. An anti-static brush or cloth is recommended.

Scumming or Haze

Increase your exposure time; washout your screen until foaming completely stops; use a wet vac to suck out the water and scum.

Use a dehumidifier to maintain 50-70% relative humidity.

Weak Stencil

Check user's guide for film/emulsion recommended for mesh count.

Use tension recommended by mesh manufacturer.

Follow drying instructions. Dehumidifier recommended in drying area.

Apply additional coats on print side after initial drying; or use higher solids emulsion.

Check user's guide for proper film thickness.

Increase exposure time. **Use Chromaline Exposure Calculator to determine proper exposure time and light source performance. Feel squeegee side of stencil during washout. If it feels slimy or you get color on your fingers, screen is underexposed. **Pure photopolymer and dual cure stencil systems may be post-exposed after complete drying for increased durability.

Poor Image—Sawtooth

Check vacuum frame for complete contact in all areas of screen.

Use dyed or tinted fabrics. Decrease exposure time.

When drying, place coated screen in horizontal position, print side down.

Film Users: use thicker film. Emulsion Users: use more coats or thicker emulsion on the print side.

Use point light source with light integrator for best results. Check bulb age.

Use Chromaline Exposure Calculator to determine proper exposure time and light source performance.

Undercutting

Emulsion of positive should be in contact with print side of screen.

Use dyed or tinted fabrics. Increase exposure time 25 - 100 percent.

Use point light source with light integrator for most uniform exposure.

Use Chromaline Exposure Calculator to determine proper exposure time and light source performance.

Check vacuum frame for complete contact in all areas of screen.