Yes, you can store transfer paper, also printed. We advise to store the transfer paper in a sealed bag which you can close. On average, in normal conditions, you can store transfer paper, sealed, for more than a year.
Some necessary conditions to make the longest lifespan out of a (printed) transfer
The transfers need to be in a closed package, in a sealed bag.
Dry room with normal humidity
We can’t give you any guaranty on this but we can say if we use this criteria you can save it for a good amount of time.