PSAG is excited to share this world-class gem with our PSAG followers. Scott 120 Used with light cancel and perfectly centered jumbo...

The U.S. 24¢ Purple stamp has been a philatelic mystery for 122 years. As explained in the articles below, these stamps are particularly dif

Here is an example of the BLUE error of color variety for the 4c Columbian – 233a. Also attached is a 4c Colombian – 233. This is an...

The following stamps are exceptional quality and would be an excellent addition to any US stamp collection. PSAG Cert 589619 This is a...

PSAG has now added an extra component - forensic analysis for color varieties.