That is a mercierized (treated cotton fibers with a solution of sodium hydroxide (lye) under tension), reactive dyed (forms a strong chemical bond with the cotton fibers, leading to vibrant, long-lasting colors) cotton sheet. High quality bed sheet.
Now as I started googling the terms, I feel that this is destroying the silver over time. If you recommend, I’ll rather purchase a natural uncolored untreated one.
Else, if nobody here has a real experience, I’ll follow Michael’s idea to use those light brown paper bags found in super markets to wrap vegetables and fruits.