TIPS FOR APPLYING EMULSION HARDENER & WHEN SCREEN PRINTERS SHOULD USE IT


Having a stencil break down during a print job is every screen printer’s worst nightmare. The good news is that there’s an easy way to combat stencil breakdown. Using an emulsion hardener keeps screens at peak performance. 

a bottle of emulsion hardener next to a coated screen

WHAT IS AN EMULSION HARDENER?

An emulsion hardener is a liquid that hardens exposed emulsion when applied to the screen. There are three main reasons screen printers would use emulsion hardeners. The first is when printing with abrasive inks like water-based or discharge ink. Stencils can break down faster with these types of inks. 

Another reason to use an emulsion hardener is to keep a screen in near-perfect condition for thousands of prints. For long print jobs, using an emulsion hardener can save the time and stress of having to remake a screen. 

Many screen printers print their own clothing brand. For these types of prints, one design can be used for years. For repeat customers, a single screen can be kept and reused when popular designs need to be restocked. Applying an emulsion hardener guarantees the screens to last a lifetime. 

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hand holding a bottle of emulsion hardener while a screen sits in a washout booth

HOW TO USE EMULSION HARDENER

Here’s a step-by-step guide to using an emulsion hardener:

  1. After properly exposing a screen, apply a thin, even layer of emulsion hardener on both sides with a cloth, brush, or sponge.
  2. Wipe off excess hardener. A film can appear if too much is left on the screen.
  3. Let the screen rest in a screen rack for 24 hours. Need to dry it faster? Place the screen in a hot drying cabinet that is 120°F for 2-3 hours.

hand spraying emulsion hardener onto a screen that's sitting in a washout booth

RECLAIMING A HARDENED SCREEN

One thing to note: screens with emulsion hardeners are permanent. They’re next to impossible to reclaim. However, it can be done. 

Place the screen in a dip tank and let it soak for several minutes. When time’s up, powerwash the screen with a high PSI pressure washer. Pressure wash the screen from the squeegee side of the screen. This method of reclaiming will take time. 

Insider’s Tip: To avoid long, tedious reclaim jobs, only use emulsion hardener on screens that will be reused, or screens for long jobs. Properly exposed screens should last long enough for many manual print jobs. 

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person putting a screen into a drying rack

Emulsion hardener is great for high-production shops or those printing the same designs over again. Invest in an emulsion hardener and save trouble and time in long or repeated print runs.