Shelf life of PnP Blue?

[BMF Effects]

I have some PnP Blue that has been printed on but I won't be able to get to etching as quickly as I thought. Is there a shelf life for this stuff or as long as I follow the "warm and dry" rule will I be okay? Thanks.

[Seljer]

I've left PnP transfers around for weeks and even months and haven't really had any trouble with it

[BMF Effects]

I've left PnP transfers around for weeks and even months and haven't really had any trouble with it

Cool, thanks!

[Mark Hammer]

Personally, I cut the patterns out of the sheet and stick 'em in an envelope.  Couple of years after printing they still transfer just fine.

Your bigger concern is notsome sort of time-related decay but the likelihood of being bent and crumbling from physical stress over extended periods of time.  Stick something stiff in the envelope to help it stay straight and you'll be okay.