3D Embossing - packing, how to prepare press and etc.
Hello everyone!
I got relatively close to achieving good 3D sculpted embossing cliches on my CNC and casting counters with different types of resins onto fiberglass board.
I am making 1:1 cast from the counter and removing the background (some thickness off of the fiberglass board) in order to not print the holes and the background of the female die.
I am probably not doing correct packing of the letterpress, because I can not get 100% if the details I want.
I have had success when putting pieces of paper with the shape of the design, or cardboard which I cut by hand. Only then it looks fine, the paper is pressed hard onto the female and I get amazing detail, however with complex design dies I cannot put piece of paper behind every element. I have also tried putting double sided tape only under the image, but still very hard for complex designs.
Is there some trick or technique in order to get nice, even and crisp prints?
I am using old manual Boston Tiegel letterpress A4+ size.
Any help would be appreciated.
Thanks in advance!
Sounds like you are off to a good start. Your discoveries are real. There has to be clearance in your “off image” areas or, the die and counter will press your sheet everywhere. Grinding away the counter board is effective and permanent. It is the best way IMO. Some prefer to “Cap” a counter. Glue a sheet to the image area and cut away, (Xacto knife), the non image area. I dont do this anymore as when the cap wears out, you are stuck. (No pun intended). This worn layer is glued down.
I will makeready behind the counter, under the plate, so pressure is very even across comple die area. Then pour.
I do use a cover sheet whi h can be easily exchanged with a new one when worn.
This process is much more involved than stated here
You wont learn it all at once. But stick to it, you’ll pick up tricks and techniques as you go. Write down problems, keeping samples, so you can discuss with others, on solutions.
Thanks once again for the insights, Eric!
I am making the counter on 0.5mm epoxy fiberboard and removing just 0.3mm from the base on my CNC.
I think that i need to remove more of the background, but in that case I need thicker fiberboard, 0.8 - 1mm.
For the “Cap” technique do you put the material on top of the counter die? Wouldn’t that reduce the detail significantly?
“Capping” the counter involves closing the press for a bout 30-45 seconds on the cap. With embossing you will want 200°-275° of heat. Then run the press ON Impression for about 2 minutes, beating the cap into shape. Cut away off image capping material. It will help fill details, but yes, it eventually will wear down, which is why I dont use this technique anymore. You can, Spot pack, under an embossing counter to bring up a weak area.
I understood what Capping means, thanks for the nice explanation.
I am thinking about using thicker fiberboard and removing more on the CNC from it or 3D printing the silhouette of the shapes with certain thickness and pack them behind the counter.
The thing is that I am able to do that on my press and have the time, but if I produce such a cliche for other person who has no experience and knows only to mount the die and print it is going to be hard time for him…
Yup…if that is all they know, it will be difficult. This craft is not “chewing gum”. There are years of tricks and techniques to learn. It is one of thr reasons experienced press operators are respected.