Why Do Plate Blocks Like To Curl Up ??

I buy albums of plate blocks and even though they have been flat in there all this time when you pull them out they like to curl up. Anything I can do to stop this?

I have the same or similar problem with some plate number coil strips. I put mine in mounts, but with some that still don't work all the time. I do think that part of the problem could be high humidity.

Peter

Agreed.

Exposure to humidity.

The gum expands more than the paper, so presto-curlo.

Mounts will hold them flat, but my SWAG (silly wild-assed guess) is that the tendency to curl will always be there, so the possibility of adhesion (to the mount) will always be there, too ... rather like the difference between the albums being kept straight-up or laid-down.

I am not sure that drying (whatever that would mean) would even help - the changes in the gum might not be reversible - but a couple of weeks in a drying book could not hurt.

Cheers,

/s/ ikeyPikey

I had the same thing happen to me.

Also, the plates they were printed were not flat most of the time, and I suspect that the printing process may have realigned the paper fibers into more of an arc then flat. Just my SWAG. Love the term, Ikey.

I'm thinking that the plates were curved, but the paper path was near-flat.




source: United States Navy. No, I wasn't, but why let a good thing go to waste on the swabbies?

Cheers,

/s/ ikeyPikey

Stickney rotary press printed stamps curl more than other stamps because they were made from paper rolls that were wetted and printed on. They were rolled back into rolls after printing, gumming and drying and before perforating in order to season. That is why they have perforator gum breaker lines added to the gum side to try to prevent curling.

Another theory about humidity causing stamps to curl. This time from a 1937 newspaper article suggesting the local postal clerk can predict the weather based on whether or not the stamps in his inventory begin to curl up:

I would think grain direction would be a variable.