Photopolymer plates: light in the room where you cut?

hi all, i was just wondering how long a Photopolymer plate can survive normal daylight? If my gathered info is correct this is best to prevent exposure to such daylight? If so, would a yellow
E27 bulb in a darkened room be the solution? Yellow: will a std yellow blulb do this trick or would i need a specific type of bulb? Where can i find such bulbs in Europe?

I know a lot of questions, thanks for any info/answers.


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OK… So, to be honest, I am more careful with how I handle the plates than the average person, and I am also probably more careful with how I store the plates as well- but I use them in a room that has windows facing indirect sunlight and I haven’t had a problem yet.

Frankly I think direct sunlight is certainly a problem- but indirect, not an issue for me with brief exposure.

I keep the plates in the dark bag until time to cut, and I slip them into a second dark bag after they’re trimmed to the size I need. Of course, I’m doing quick cuts on plastic backed plates using one of those office shear/guillotine trimmer type of things. Not cutting metal plates. So there is a bit less time spent “in the light”.

But frankly, indirect exposure is way less UV light than would pass through the cover and do any real damage to the plate itself- so it is worth mentioning this is just being left in light while handling.

I wouldn’t bother with the bug bulb, for that matter. I think probably you’ll be better off installing a window shade if possible.

If you have Fluorecent Lighting, there are UV Filter tubes which slip right over the Tubes, turns the entire space into a safe Light room for Polymerplates, I make them professionally and this setup has served me for decades.

That’s some real usefull info :-) Thank you both.
Yes my room has a rooftop window, as such there’s some direct light possible during cutting. I will try to blind that window to the maximum. In the room there’s one E27 socket as such i’m trying to figure out which lightning won’t harm the plates when i leave them out of their bag for ca. 2-3 minutes (read: the time to cut them down to size and rebag them).I For info: i bought metal backet plates 95mm to start with as i’m a newby (although i made some plates last year and where quite ok; then i waited till night and lit op my small smarphone led pointing to the ceiling in a corner of the room to give you an idea in how much i try to keep them out of the light).

An idea: is photography darkroom lightning a solution for this too?

Yes, ideally you would do this all in the dark with darkroom lighting; however, I think if you put a shade up or blind the light you should be fine for 1-3 moments, especially if you’re careful and turn the plates OVER when you’re done cutting; the advantage of the metal back is that it doesn’t transmit light, so this would be safer than leaving face up.

Light can still creep in from the sides, of course, so doing as you have been and re-bagging is the best way.

Plateroom lighting is adequate (yellow light) as opposed to darkroom lighting (red light). Or just subdued light.

I turn off the spot lights above the equipment in my shop while I do the plate cutting. Only the ceiling fluorescent lights are on.
These are the filters I have on the fluorescent tubes directly above my plate-maker. They are about 4ft. from the plates!
I never had a problem with stray exposure on the plates. The plates are exposed to ambient light only while they are worked on.
One of my plate suppliers had the rear garage doors open all day long during the summer. They never experienced a problem either. These plates are pretty much selectively UV-365nm sensitive. I am using JET-USA plates and don’t know about other brands.


This week-end I am getting a Repromaster Mark 3 and turning my shop in to a Red Light District! The film IS daylight sensitive.

image: EncapSulite.jpg


Ok, i’m becoming a bit wiser along the way: i’ve found an interesting webpage which shows the UV-values of certain lights. This could be helpful for future newbies who want to figure out which lightning is safe to use.

Long version:

Short version: Ikea 10w 3000K led light seems to give the best lightning and has a very low UV-value, thus would fit the purpose :-)

Thanks all for your help.
Greetings from Belgium,


Louie….enjoy your Repromaster…..I did.

Thank you jonathanjeclipse,
please see my questions on my topic of:
Negative film supplier in Toronto