Question About Gum On Sc#1932-33

Do SC#'s 1932 & 1933 Babe Zaharias and Bobby Jones issues of 1981 have a different gum than the other stamps of that era? I'm pretty sure everything in my main US album for that era is MNH OG. However both of these appear to be mint no gum. Out of curiosity I went to ebay and ordered a Sc#1933 plate block (it was just as cheap as a single) that was advertised as MNHOG and it also looks like no gum. All my other stamps from that area obviously have gum, most shiny, some not, but obviously still gummed. Sc#'s 1932 & 1933 look as if they have no gum, but Scott Specialized doesn't mention anything about that.

YES...it is a dry gum.
There is gum there....does look like no gum.

Thanks Kevin.

Why is this dry gum only with these 2 issues? None of the other stamps I have around this era have this type of gum.

I went to my issues of the golf stamps and they are as Kevin said not shiny. Perhaps this was something they tried out at one time.
Tom

Several of the stamps in the Transportation Series have this type of "invisible" gum. As a matter of fact sometimes stamps of this series are offered on E-Bay with the notation "no gum"! It seems though that the only printer using this type of gum was the BEP at that time!

Peter