I am new to letterpress and was doing an invatation of a combo of bold and non bold letters. The problem that i ran into was this. One bold letter would not print full in the enboss after running about 7 to 10 it would be spotty. The first 5 would be good. then it would start to get spotty. Only on this one letter. When this would start happening you could let the plate ink a few times then run one and it would be good.Any ideas? It is a Kluge press and photopolymer plate.with a combo of hard and soft packing.Hard on bottom getting soft near the surface of the packing.
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Poly is strange and will do things like that to drive you crazy.
If you are using rubber base ink and have the least bit of oily contamination on the plate, it will reject the ink. Clean with alcohol (as it dries fast) and try again.
Next, if required, move the plate or turn chase upside down and try again. Don’t forget to move the pins. Probably best to just remove the pins and tape a piece of stock to the platen. These tests will lead to the answer to the problem.
I’ve had this challenge before and I cut out a text weight piece of paper the size of the letter, raised the photopolymer and placed it under the letter. This raised the letter to print evenly with the other letters.
If the paper interrupts the letters on each side then cut the letter out of the photopolymer and place double stick tape under letter and stick back down and this will raise it.
A fresh exacto knife blade and magnifying glasses help.
Thanks for the reply .Inky what you said makes sense. Thanks alot. Cmcgarr i did what you said tonight and it did turn out better. thanks to both of you for the information.
If it works - turn the Form, cut the Letter from the Plate and raise with tape.
What is if the Plate is metal backed ?
Here is a movie from a friend of mine who is simply one of the best Letterpress printers in his Neck of the woods.
What he does with the cut and pasted paper pieces is called make ready, it applies a tad more pressure in a specific spot.
This old skill applies to any cylinder, platen and handpress.
In my experience photopolymer plates give you exactly what you ask of them. If you are messy or shortcutting you sort of get a scenario like the old folk tale of the princess and the pea.
I would suggest never using a soft packing with any kind of exact planar surface material, especially photopolymer. If you have to do makeready on a plate to compensate for an individual character or isolated imaging you either likely have a bad plate or your presspacking is matrixed from previous impression.
If you are having a cyclical pattern problem as you seem to describe, I would suggest this may be a press problem.
If not the press, assuming you have not previously encountered this, and since your bold character is running apparently low on ink, compared to the other characters, a better solution would be to run the bolds separately.
You’d have better control over the inking. Sometimes a problem unresolved will slow you down a lot longer than two separate runs, and without the frustration and cost of ruined material. But that’s just a bit of old school thinking.
Or, not as good but probably good enough, do as previously suggested with either interlay or overlay.
thanks from everyone.I will go back and modify and adapt. Again thanks to all.