Hi guys..I was going through my junk box (stamps I have not analysed yet) and found 3 stamps..One 5 cent and two 15 cent.
I looked on the
E.S.J. van Dam website and found information about the 15 cent varieties as shown below..

It mentions the rarer stamps are Perf 12.0 and on white paper...below are my 2 stamps and the one on the right seems to be white paper.




I am thinking these could be the white one they are referring to with whit paper and different perfs.
Need an outside opinion..Thanks
Robert