Do collectors do a good job differentiating between engraved and lithographic issues?
In my experience - No!
The 1911-21 (engraved) and 1913-23 (lithographed) Greek sets for example...
1911-21 Scott 198 1 lepta green "Hermes" (engraved)
1913-23 Scott 214 1 lepta green (lithographed)
The collectors on this thread are quite sophisticated about the differences. But many collectors have difficulty.
Let me tell you my experience.
I was transferring the two issues from a feeder Scott Specialized Greece album into the Deep Blue (Steiner) album, and. thinking the previous owner was no doubt somewhat of a specialist in Greek stamps, I would check the printing type after I had finished.
When I got around to doing the evaluation, I had quite a surprise. Of the "engraved" stamps, 10 out of the 15 stamps I had placed were in fact lithographic stamps! And I found an engraved stamp among the lithographic issue spaces. So confusion indeed!
Is there a technique for determining the difference besides examining the stamp?
1921 Scott 212 10d deep blue "Hermes carrying Infant Arcas"
Stamp rubbed with a pencil eraser with aluminum foil over stamp.
Will leave an impression if engraved. (Recess)
Will leave nothing if lithographed. (flat surface)
Another tool for the collector.