The genuine issues are line perforated 12 (Mi #1-3) or 9 1/2 (Mi #4-6). Although several perforation errors exist, Michel does not list any imperforated issues of these first stamps. The second issues of 1867 (Mi #9-10), however, are imperforated but have values of 1 Para and 2 Para. My issue could therefore be a grave mistake by the forger, or a sample where the perforations were not added (or were later cut off). The shown forgery has some similarity to Billig's Type II forgery [1], but he does not mention any imperforated versions either. This could therefore be a third type.

The most obvious design characteristics are:

1. The feet of "K" and "A" in the heading are connected on genuine issues
2. The ear of the Prince has a strange shape/shadow on the forgeries
   
3. The last "A" in the denomination (PARA) has a pointed top on genuine issues
   
4. The head of the "1" in the denomination should be quite small on genuine issues
   
5. The denomination in each corner should be much more narrow and precisely drawn
   

Forgery	Genuine

Forgery

Genuine

Again, this forgery has some similarity to Billig's Type II forgery [1], but not as an imperforated version. This could therefore be a third type, or a sample where the perforation is later cut off. The most obvious design characteristics are:

1. In the "SRPSKA" heading the Cyrillic "b" should have a longer head, the "C" a smaller opening, the head of the "K" should not be "hanging", and the feet of "K" and "A" should be connected. (All these characteristics also apply to #1 above, but they are hidden by the cancel on my sample)
2. The ear of the Prince has a strange shape/shadow
3. The "A" in the denomination (PARA) should have a pointed top
4. The denomination in the upper left corner should not be broken