Sometime in 2016, a few eBay listings popped up offering for sale ‘Rare Red Line’ US stamps. Most experienced hobbyists simply ignored these silly listings since they understood that these lines are not ‘rare’ at all. They also understood that they are not ‘errors’. But apparently other sellers saw these listings and began offering their own ‘rare red line’ and ‘rare error green line’ stamps; often at astronomical prices. Before anyone knew it, eBay filled up with these nonsensical listings and it was not long afterwards that stamp forums began to see people asking questions about them.
US stamps with ‘red lines’ or ‘green lines’ often occurred on flat plate stamps that were located along the outer row of stamps. Typically sheets of stamps were printed and then cut by the PO into smaller panes; it is these panes which were distributed to post offices around the country. Many of the sheets had lines on them to designate where the panes were to be cut apart. So on any given sheet, there may be stamps with either horizontal or vertical lines. These stamp will also not be perforated on that side. Hobbyists called these stamp ‘straight edge’ and most find them much less desirable than a fully perforated stamp. As such, the value of these ‘line’ or straight stamps is actually less than a fully perforated stamp of the same variety.
So when you see an eBay listing for a ‘rare red line’ or ‘rare green line’ you can be assured that the seller has little or no knowledge about stamp collecting. The following images clearly display the lines and where they can located on a pane of stamps from that era.