Limitations home made polymer

Hi, I have a beginners question. English is not my native tongue but I will describe my question as clearly as I can.

I’ve made a polymer plate (steel backing) with the use of a self made film produced with a photocopier at the local grocery store. I’ve made it as black as possible and made two runs. Then I spayed some blackener on the sheets and put them on top of each other so they aligned perfectly. Next step was the 3M plate developer(?), you know the machine with the uv lights and produced two plates. The first one was no good due to the short time it was exposed to the uv light and the second one seemed just fine. At the time of printing I noticed that the double-story lowercase g was filled up with ink between the upper and lower part and the www of the webaddress was filled up aswell. I used Erik Spierman’s Fira Sans type 10pt in InDesign to produce the type. Am I pushing the limits of polymer plate printing, or is this just a beginners error with properly washing out the plate?

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Hello Coen, in order to get quality plates, your negative has to be perfect. Where are you based? Have you considered getting a proper negative produced for you? Also, what kind of film are you using to make your own negatives, laser printer or inkjet? Please give some more information…

Hi Thomas, I use sheets that are especially ment for photocopiers. I’ve thougt about having films made but they are very expensive due to starting costs every time tou want a film produced hence the 3M plate uv developer I bought for 100€.

“Am I pushing the limits of polymer plate printing…”

No, but you might be pushing the limits of your equipment, tools and experience.

That is fine if you have to, a lot of us work with tools that could be better for a variety of reasons, be they budget, availability or simply to challenge ourselves (such as those members who build their own presses).

If your plate turned out well enough that you only have a couple of small mistakes in the plate, on your very first go, you might just need to tweak a variable in the process and try again.

One of the trade-offs in using less-than-great tools is you often have to put in more time, and waste a bit of consumables, to get the results you want. You have to feel out the limits of your skills and materials.

If you can find better film, that will eliminate the most likely issue. It might be worth buying some film just to confirm whether that is the problem, rather than spending time and effort chasing down other variables that might not work out.

Best,
Kim

Thank you for insights and thoughts there Kim. Very clear and usefull. I will try again. If it doesn’t work out there’s always some metal type to fall back on or invest in a professionally produced film. ;-)

Hi Coen, If I understand the process you described you aligned two photocopied sheets together and exposed your plate using that sandwich.
Plate makers would arrange things so that the emulsion side of the film is down against the polymer plate to prevent any light from spreading under the film. Having small areas filling in with ink on the plate could be caused by light spreading under the film and exposing polymer that should be protected from light by the film’s emulsion.
In the situation you have described having two films you may or may not have the film emulsion down. I would check that. Also trying to align two films exactly might not be possible. It may look aligned even under magnification but that might not be enough. Photocopiers are not made to produce great quality or exact copies.
Also I’m not familiar with your 3M developer but if your films are stacked you would want to have a point light source and not a flourescent type bulb.
But hey, You might have stumbled onto a great way to create interesting effects that no one else can do.
When I was in college I took a course in photo plate lithography and a visiting artist laid out a sheet of acetate, rolled black ink on it. flicked gasoline on it and proceeded to make some pretty wild prints from that.

I very occasionally use films that silk screen printers use, it’s a translucent film, not a transparent one! I use a HP laser printer, a very old model that apparently gives a nice black print. I spray them to obtain a truly black film, but even then, you will never get the results that you get with a proper negative. I rather pay 15 € for a top quality film and make plates without problems. In the end you incorporate the costs of film, plate and equipment – and don’t forget time – in your price. Recently, I had to change 6 UV tubes and the brush pad. 120 € for the tubes, 180 € for the pad. If you don’t take these costs into account, you might as well forget about it! Be realistic, if your customer doesn’t want to pay for your work, you shouldn’t take the job…

Bruce and Thomas, thank you both for your comments. Very usefull tips given there. I will take it in account next time I make new plates. It’s more of a hobby Thomas, I don’t have any customers. At the moment that is. Maybe when I professionalised my letterpress adventure I will be ready for some customers. Would be sweet if it wasn’t in the freezing garage where my tools are now. ;-)