Identifying the difference between a lithograph and offset print – or how I spotted few forgeries on spanish stamps
I was preparing some scans on unwanted (duplicate or mint) items for my stamp exchange website when I noticed few mint Spanish stamps that didn’t seem to fit into picture. The subnotes on stamp catalog confirmed my hunch- I had stumpled upon forgeries of somewhat common and cheap stamps.
The original issues were printed using lithograph (”stone printing”), the forgeries were printed using offset. I know many collectors struggle with how to tell these apart - especially if having nothing to compare with. In reality the difference is quite easy to spot if you know what to look for.
First, here’s a real stamp printed in litho. A lithograph print will ALWAYS have a solid outlines and fills. The print impression is flat with no notable indentations differentiating design from paper/non-printed areas (both front and back feel flat/smooth when you when you touch it with fingertips).
And here’s the forgery printed in offset. Especially post 1920’s stamps offset means that stamp is printed using photogravure. The characteristics for this are simple, as the impression ALWAYS shows lines of dots (or beads) when looked at proper (at least 10x) magnification. The dots will be visible on both the outlines and fills. The resulting impression is generally unclear and flat when compared to litho:
Instead of going to trade, the forgeries ended up into my collection.