by Scott Martz
In previous columns I have focused on plate varieties, but today let us look at a printing variety. The pictured stamps are: #529a— three cent purple, type III, offset printing, double impression; and #530a—three cent purple, type IV, offset printing, double impression.
These are spectacular double impressions, showing great distance between impressions. They almost make you think your eyes are out of focus. It is interesting with offset printed stamps the paper is not actually printed twice. The plate puts ink on the transfer roll twice. If the transfers are slightly apart then when the paper does go over the transfer roll, both ink impressions are transferred to the paper at the same time, showing the double image. This also explains why 1 image is slightly blurry, and less distinct. The ink was disturbed from the first transfer by the second, so the second transfer is bolder and clearer.
These are not rare varieties for the offset series, and can usually be found at a large stamp bourse. These three cent denominations can be had for only $20 to $30 dollars.
Happy Hunting! Scott