Dave, I can see how this will help sharpies.
Glue, super glue, goes bad so fast I buy it in 10 packs. yikes.
Another thing that goes, masking tape. It peels well but once it dries out, it shreds easily and I use a lot of masking tape.
What comes to mind for me is art supplies. Especially acrylic pens, the kind that have paint in them, used for painting. We use them occasionally for decorating pumpkins, or drawing outlines on landscape fabric in the spring. When the seals are opened, they begin to degrade and they can't come back from dry because acrylic dries and can't be rehydrated.