Slightly OT: rubber stamp inks
2013-01-29 by Tony Sleep
This may give fine art workers the heebie-jeebies so I apologise, but I hate to let prints out into the wild without a copyright stamp on the reverse, giving contact details. This is sure to become even more important thanks to the determination of governments to legislate routes around copyright for orphaned works. Back in bromide days I used rubber stamps with ordinary black dye office inks. On RC papers I used solvent-based inks that adhered to the polyethylene coating. Print through was never a problem. Later, when I was producing a lot of prints for repro, I printed labels and used them. None of these have actually proved to be an archival problem so far (uo to 35 years). With inkjet, I did experiment with printing a very pale gray stamp on the reverse of the print on most materials without any damage to the image side of the paper. However it always felt risky and a bad idea. With my old Epson 1290+Piezography inks it was successful. With my current HP it is disastrous, physically marking the surface. So I am back to a rubber stamp again, but ink is a problem. Ordinary black pad ink is far too dense and print through is likely unless the ink pad or stamp is almost dry. Stamping once on a bit of office paper before application of stamp to print ensures the stamp isn't overloaded, but the problem then is often an only partial impression - which is hopeless. There is no such thing as pale gray on the market, which is what I think I need to get a consistent, tidy and predictable result. But what solvent to use to dilute black without encouraging too much penetration of the paper and print-through or leading to long drying times? I haven't had much luck finding out how pad inks are formulated, only that their are dye, pigment and solvent dye types. It could be as simple as water or water+alcohol, but I just don't know. I suspect there is some gum or PVA or similar added to proprietary water based stamp inks (to get even ink take-up on the rubber) and the concentration may need to be maintained. I'm happy to experiment, but some sense of direction would be useful if anyone is less clueless than I am. Alternatively, has anyone experimented with any of Paul's DIY archival pigment formulations and found that they are "stampable"? -- Regards Tony Sleep http://tonysleep.co.uk