Current Ebay listing for RB31p with an alleged "plate crack"
Currently, a dealer on Ebay is selling the above copy of a 5c proprietary battleship with a printed cancel for a $75.50 Buy It Now price due to a supposed plate crack running across the top portion the stamp. While it may not be perfectly visible on this site, there is a clear, straight line running through the center of the left 5 on the stamp. This line the dealer has labeled a plate crack.
While I am not an expert in printing techniques of the time, I am fairly certain that this is not a plate crack. The line was placed on the plate on purpose by siderographers laying out the plate. The line was used by these technicians placing the impressions of the stamp from the transfer roll on the plate in order to lay out the subjects in neat, straight and squared rows.
These layout lines should not exist. Normally they would be burnished off after the plate was produced. In some cases, and this is one, they were not. This particular line is solid and quite strong, which makes it stand out from the stamp. While this may seem like a special item, there are literally tons of battleship stamps out there with evidence of these types of layout lines.
Don't be fooled, and certainly don't pay $75.50!