The Photo Polymer

I have not used Photo Polymer plates since about the same time OSHA came around, and ruined everything. One of my duties as an apprentice was making hard photo polymer plates that I would use to crash imprint multi-part forms on the C&P, or windmill. In the mid 70’s, about the same time Linotype was winding down, the Photo Polymer process was relatively new, very messy, and probably quite lethal.

Back then, the chemicals used in photo poly made my knuckles break out in watery blisters, and still causes me to drive really slow in the far left lane. Maybe OSHA had a point.

I was wondering if the Photo Polymer process is any safer since the ‘70’s. Thinking of getting back into it, as an alternative to mag plates for short-short one-time runs

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Yes, the plates you were using were probably Nyloprint or Kodak Relief Plates (KRP), which at the time were washed out with alcohol and or caustic solutions in an elevated temperature bath. Not entirely ecologically friendly or absolutely safe.

The plates used most often these days are water washed and much more environmentally safe and user friendly. You would enjoy the changes. You may still have a reaction to the photoinitiators in the wash-water, so if you make physical contact with the washwater, it would be suggested that you use rubber or vinyl gloves to protect your hands.

Jim- I had the same problems years ago with the earlier photopolymer plates. They were not kind to skin at all, and they smelled odd. The newer plates are not nearly as bad.

Most modern pp plates are water washed, and are qutie fun to work with. I’m not 100% convinced that they don’t contain some dangerous chemicals, so I wear gloves whilst washing them out.

Now… about OSHA…. they are a two-edged sword. They have indeed prevented a lot of injuries and illnesses in our industry. Unfortunately, they have also gone overboard in many ways which has made operating a letterpress-based business problematic from a legal standpoint.

Thanks for the info. I see a lot of comments here (Briar) about PP plates, and just wondered why they are so popular, considering my unpleasant experiences with them.

The thin, hard plates for crash imprinting were the worst, but for a while, I also made the softer self inking stamps. Rubber gloves worked fine, but if a pinhole developed in a fingertip, my hands would be swimming in chemicals for an hour or so. This made breathing type wash fumes eight hours a day seem benign by comparison.

Pressured by industry watch dogs — such as OSHA — the producers of photo polymer resins were eventually forced to include warning labels. “… may cause allergic skin reaction.” I thought, “Oh, NOW you tell me.” Sometime between then and here, they changed the chemistry completely. Again, thanks for the info.


The type of photopolymer you used in the past is still available and practiced. For most letterpress and an increasing amount of flexography, water washout sheet photopolymer is now the norm.

It is far safer than the materials you describe but there are still warnings and precautions issued with the plate material regarding skin exposure, eye protection, proper ventilation, etc. This has far less to do with OSHA (now a rather ineffectual government agency) than it has to do with avoiding possible litigation.