You are right, those 6 are all soft porous paper. The wide margin on stamp #2 and #5 clearly show the "checkerboad" pattern of the soft porous paper.
Many copies of both Scott 179 and 185 have a blue surface from poorly polished plates during printing. This ink can tend to mask the paper texture. Viewing the paper from the back is normally helpful.
The last stamp in question is soft porous paper. I magnified your scan 400% (by the way nice scans) and marked the characteristic soft porous paper pattern in the margin. I hope this will help.
Posted 03/23/2011 1:26 pm
