Emulsion & exposure · 1 of 7 · 1 min read
Emulsion types
| Type | Strengths | Trade-offs |
|---|---|---|
| Diazo | Lowest cost, widest exposure latitude, forgiving | Slow; thicker stencil; must be sensitized; about 3-month life once mixed |
| SBQ photopolymer | Pre-sensitized, fastest, fine detail, shelf life about a year or more | Narrower latitude; many aren’t water-resistant |
| Dual-cure (diazo + photopolymer) | Wide latitude, good detail | Must be mixed; about 3-month life once mixed |
| Capillary film | Very consistent thickness, smoothest stencil, saves screen-room time | An old reputation for delamination; Vastex says current products run long |
Which one first? ScreenPrinting.com suggests matching the emulsion to your ink and exposure unit. For units without a vacuum, or with fluorescent tubes, it recommends a dual-cure (diazo plus photopolymer) emulsion as more forgiving; with an LED unit plus vacuum, nearly any emulsion that matches your ink will work.
For water-based and discharge inks, pick a water-resistant emulsion or add a hardener. Murakami notes that under-exposed stencils peel on discharge and water-based runs.
Sources for this guide (22)
- Davis International, Emulsions
- Vastex, Emulsion information
- Dalesway, Screen printing emulsion
- Murakami, Emulsion coating tips (PDF)
- Murakami, Successful emulsion coating
- Ulano, QT-750 tech data sheet
- Screen Printing Magazine, Stencilmaking in the age of CTS
- Screen Printing Magazine, An update on UV LED screen exposure (2014)
- ScreenPrinting.com, Compression vs. vacuum exposure units
- Printavo, Exposure calculator
- ScreenPrintingNow, How to use an exposure calculator
- ScreenPrinting.com, 4 steps to consistently reclaim screens
- Chromaline, Causes of pinholes during screen making
- Chromaline, Underexposed screen tech tip (PDF)
- Chromaline, 10 common reasons for stencil breakdown on press
- ScreenPrinting.com Help, How do I figure out exposure times?
- ScreenPrinting.com Help, Over- vs. under-exposure
- ScreenPrinting.com Help, Which emulsion should I use?
- ScreenPrinting.com Help, How long do screens need to dry?
- ScreenPrinting.com Help, Making a darkroom at home
- ScreenPrinting.com Help, Do I need a pressure washer?
- ScreenPrinting.com Help, How do you reclaim screens?
Ranges are starting points from these sources. When a source and your ink’s tech data sheet disagree, follow the tech data sheet.