It’s crazy how time flies, it’s been 20 years since I first discovered to use photopolymer plates for metal clay!
Before this they had been used by the industry for printing cardboard boxes and other large packaging and by artists like myself, for printmaking. Photo etching and block printing became an exciting medium for me in art school but I had not used the plates for a long time until I started working with, and teaching metal clay.
Metal clay in its soft state in very floppy and perfect for organic shapes and pattern, but I needed very precise lines for my champlevé enamels which proved to be a challenge with metal clay until I remembered my old printmaking techniques and tested them on the clay.
They became incredibly popular as soon as I shared how to process them on my metal clay forums and later did a presentation on them at the 2006 PMC Conference in the USA.
I also did a second presentation there on how to prepare the artwork for PPPs using image editing software such as Photoshop or similar. These days I use Affinity Photo which makes it easy to print out exactly what I want.
How to create the perfect artwork to expose Photopolymer plates
How to Prepare the artwork for a Photopolymer Plate
A FEW key points you need to remember:
All artwork has to be Black and White, no greys!
Don’t make your lines too fine, the PPP can take it but it’s nearly impossible to get the clay out of those lines in one piece.
Whatever is black in the artwork will be raised silver in the finished metal clay piece.
The metal clay will shrink, each brand is slightly different. Check your manufacturer’s instructions and make sure to adjust the size of your design to allow for that.
If you are using text you need to make your artwork mirror image, you can do this by place it upside down on the plate in the exposure unit.
Create or scan the art into your computer using a 300 dpi resolution. This will give you enough fine detail while working on it in your image editor ( Photoshop or Affinity Photo) but without too much clutter.
In Photoshop (or equivalent) go to: Image > Adjustments - in the Menu bar - increase the contrast by using Levels, and then add contrast to get a perfect black and white image. Aim for a good balance of black & white lines. Make sure you have enough white space around the print, this prevents unwanted marks on your clay later.
Double up the image in Photoshop, so you’ll print out two identical prints next to each other as one image. If your artwork was done to be correct for the PPP you’re all done. if you need to invert to colours you need to do that now. (remember black will be high, while white will be low in the finished silver piece)
Print onto an overhead transparency at the highest quality your printer will allow. If you are using an inkjet printer you need to get special transparencies, most brands have their own, but generic inkjet brands work fine as well. Any large office supply store stocks these.
Cut the transparency in half so you have 2 separate images, cut one bigger that the other to make it easy to tape them together.
Place imges on top of each other so they line up perfectly → putting them on a sheet of white paper makes it easier to see the fine detail. Use clear sticky tape on 4 sides to keep images securely together. You are now ready to make a Photopolymer plate!