Manual Washout Photopolymer Plate Making

I’m wondering if anyone can help me with my plate making progress. I have a small desktop photopolymer plate maker (polydiam 250 v) and I am having troubles getting fine lines to washout. I have reduced the exposure time to 3 mins which seems to work fine. I washout manually and have tried so many different ways to ensure the fine lines do not wash away. If I reduce the temperature of the water, the excess polymer takes too long to wash away, causing the fine lines to break away. If I increase the temperature of the water the polymer washes away quickly however it seems to melt the fine lines. I’ve tried several different brushes and been very soft on the plate, however nothing seems to be working. I have played with different exposure times also and have not been able to crack it for really fine lines (they are above .25mm). If anyone can lend some advice, that would be great. I’m wondering if it’s possible to get the clarity I want on my small plate maker with manual washout???? Thanks!

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What kind of negative are you using and how are they processed? Just because your digital file has a line .25mm thick doesn’t mean your negative will be that size, unless output professionally on a high-res imagesetter.

I would use a stouffer scale to establish proper exposing time, get the mds from the vendor for the plate substrate and adjust the water temp and time to spec.
If you have Lines of 12 pt type and a hairline of .25 or less, the Line will always suffer. polymer needs to sit on a base to be able to perform accordingly.


What brand of plate are you using?

To some extent, you should not expect to get a perfect washout by hand, there are far too many variables at play; it depends upon your personal needs.


Thanks for your replies so far. I am getting the negatives made professionally using an image setter on very high quality photography film. And I am using tyobo polymer from boxcar press. I have ordered one of their washout brushes this morning so am hoping that may make a difference but any other tips would be really appreciated! Thanks a mill. Susie

Hi Everyone, I wanted to give you all an update on this topic and close the loop for anyone else who is finding the art of plate making challenging! Firstly I’m thrilled to tell you that I have refined the process significantly….. I started playing with the exposure times and have improved on that, however the massive difference came with the type of washout brush I was using. I had been experimenting with all kinds of brushes and none of them would work…. so as a last resort I decided to order a washout brush from Boxcar and it arrived last week. It has simply transformed my plate making life! The polymer comes off so much easier and quicker and my plates are now getting the definition I wanted…… I had my told and read by so many that a $2 nail brush would work just as well but in my experience, this is not the case. The $30 Boxcar brush is the best investment I have made (along with all of your tips above of course; thank you again!!)