(Grill Like Impression Wtheck) On 1938 One Cent Washington Coil Strip Of 3

interesting I came across a long with another different stamp ben frank coil stamp also
Can anyone shed some light on this interesting find.

Without scans and a litlte more to the questions, it is impossible to give you any advice.

Those are 'gripper' marks that come from the coil stamp dispensing machine. The grippers help feed/advance the coil stamps through the machine.
Don

Don beat me to it while I was looking for a good example and getting good side-lighting set up, in this case a paste-up single used in 1913.



Typical of stamps sold through vending machines in post office lobbies, drug stores, hotels, etc. Thus easiest to find on 1 cent stamps and on tourist postcards.

Some would call these damaged and seek different copies, while others would consider these to show evidence of the "postal history" of how coil stamps were sold/used in this era.