Holden's Photo Emulsion 250WP is a premium photo emulsion to be used when water resistance is the primary need. It has all the characteristics of Holden's Photo Emulsion 250, but is more desirable when working with 100% water based systems.
From the product label:
WATER RESISTANT - RECLAIMABLE
Specially formulated for short runs and machine printing
250 WP is recommended for use with water soluble inks, textile pigment emulsions (oil in water type) and plastisols.
INSTRUCTIONS: Dissolve powder in a small jar with cold water. Mix dissolved powder into emulsion. Stir slowly with wood or glass paddle. Allow any bubbles to disperse. Mixture now has a shelf life of 4-6 weeks at room temperature. Develop screens with cold water. KEEP IN A DARK PLACE. For longer shelf life, keep refrigerated but DO NOT FREEZE.