Backside ghosting while Foiling
A common problem I have when foiling is seeing a ghost of the image on the back of the sheet.
My project yesterday and when I get back in on Monday are on black paper. I try to be very conscious of pressure during makeready/setup but by the time I get an acceptable image I can see a latent ghost on the back on the sheet; enough to be objectionable.
The work is done on a 10x15 Windmill with Owosso magnesium dies, phenolic board and (typically) Crown foil. (Their new minimum order policy has us also using another vendor when necessary.)
My basic rule of thumb is to run a sheet or two increasing pressure/makeready until I can just make out the impression even before loading the foil. Our heat standard is 235 degrees (f) but I have been known to take that way up or down as necessary. (To my understanding lower the heat if you fill small reverses/type or flake at the edges.)
I try for and achieve “offset quality” while foiling. I have samples of my predecessors work and much of that is very sub-standard. I also have a sample of the last job produced by a larger facility using the exact same die and paper that shows a clean back of the sheet. (They produced a pocket folder. I am using the die(s) from that job for single sheet report covers.)
Is this inherent to the platen process? Is this tied to the phenolic board? I don’t think there is a heat/pressure sweet spot which will give me my holy grail of foiling.
In my experience, the phenolic board does cause a noticeable burnishing on the backside of the paper.
What I do is insert a very thin newsprint paper on top of the phenolic and that usually makes the burnish disappear.
But if you have too much pressure this won’t do.
What I would try is this first, and then more heat with less pressure to see if that makes it better.
Just my humble opinion, but maybe others with more experience will chime in.
Thanks for that tip enriquevw. I’ve used tissue and foil over embossing dies but this is a new idea for my box.
pass