I realize that Baseball Salesmen Samples get most of the attention whe it comes to such things but Topps issued these little teasers for most, it not all, of their standard card sets through 1967 or so and the 1963 and '64 Football samples below are one such example:
The reverse is quite wonderful:
That "special feature" may have been fun to rub off as a kid but it certainly bedevils modern day collectors!
Sometimes samples got cut up, probably by a wholesaler's or retailer's kid:
1964 brought this; I have to say I'm not a fan of this design as I want to cut along the stars, which resemble dotted lines to me:
Too bad these ended prior to 1969-the first series Football cards from that season would have looked stupendous given their full bleed borders-this uncut sheet certainly gives you an idea though: