But are they? They most certainly do not include the name of the country or a value, nor does the design cater for the future inclusion of either. I know that's not foolproof evidence, but to me they look more like private engravings, practice pieces maybe even, than proper stamp essays. Especially when they're so readily available and many are signed as well. They also come in a long row of other Wimmer 'essays' portaying either J. F. Kennedy or including scouting symbols. Again, we see engravings without the mention of any country's name or value.
So basically, I haven't a clue what these really are, and I would appreciate someone (anyone!) with authority to comment on them. Having said all that, they are great to collect because they come in many shapes and sizes. Most popular one is the sunken die proof, as shown above, on card. These are usually the signed ones.
|Schubert die proof, state 1|
|Schubert die proof, state 2|
The Kennedy essays, which I don't have so I can't show them yet, may also be found with perforations and on variously coloured papers. All in all they may or may not be proper stamp essays, but they're great to collect and then show how engravings and subsequent proofs are made, thereby giving more insight in stamp production as well!