With the proper care your Sam Hober pocket square should last for many years.
The easiest way to keep your linen pocket square crisp and prevent shrinking is to dry clean it at a reliable dry cleaning establishment, one that has experience with fine linen fabric.
If you hand wash your linen pocket square it may shrink, especially around the hand-rolled edges and the texture will soften. Do not use a fabric softener, or starch.
In a true emergency Sam Hober pocket squares can be spot cleaned with just a little cold water on a cloth. Then dry by very gently rubbing a dry cloth against the linen. Please note that this is not always going to work! The old advice to use soda water is no longer necessary. Long ago water often had salts in it which would chafe the silk. This is no longer the case with the water supply in most places.
Do not store your pocket square in a plastic bag. For long-term storage, place the pocket square between cotton sheets.
Line drying in the sun works very well. Do not wring your linen dry, or use a dryer. Over drying is not good for linen and will result in broken fibers.
Pocket squares can be ironed on the inside flat area. Be careful not to iron the hand rolled edges. Iron when the linen is still damp, and press with a warm iron.
For deep wrinkles a gentle steam from a steam iron or steamer should be used before ironing. Also, be very careful when steaming as occasionally steamers “spit” water which can cause water spots.