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:
What offset usually means (especially post 1920’s stamps) is photogravure print, and it will ALWAYS show lines of dots (or beads) of color when looked at proper (at least 10x) magnification. The dots will be visible on both the outlines and fills.
Lithograph print on the other hand will ALWAYS have a somewhat solid outline and fill. In lithograph, the paper is flat and there will be no notable indentations differentiating design from non-printed areas (except maybe on the top).
However, if you feel the printed design from the back of the stamp, then the stamp is printed in typography (also known as letterpress).
Below are some images to tell the difference using visuals between lithograph and offset (photogravure) print.
First, here’s a real spanish stamp printed in litho. Notice how firm the borders and fills are.
And then a forgery printed in offset (photogravure). The print is very unclear and there is a visible dot pattern especially on outlines.
Instead of going to trade, the forgeries ended up into my collection.
Knowledge is power!