[ALR-bishop]

Finished Salesman Samples do not have blank backs.

I think it is usually impossible to tell if a blank back card or strip or sheet is a proof or an error unless the card, sheet or strip shows a player pictured differently from an issued card ) like the 77 Jackson as an Oriole, or the 67 Maris as a Yankee, or the 84 Topps Encased cards), or came from Topps vault designated as such, or appears to be a progressive color proof ( that is clearly not a faded card ) .

I have seen blank back verified proofs sell for large premiums, blank back errors for lesser premiums.

I have collected the Topps 1985 Mini set in regular back, blank back, red back only, and distorted backs. ( have completed it only in regular and blank back). The blank backs can be tan or white. Since the whole set is essentially a non issued test set all versions of the non regular backs tend to sell at a premium over regular backs.

Several examples of blank back cards have been posted in the never ending variations thread. I think the value of any particular blank back star card is hard to predict.