That's quite interesting !! You might try to take a alcohol swab and remove the writing !! Hate when people use a felt tip on stuff !! If you know anyone that's a nurse, works at a hospital, or is a diabetic,,they will have the alcohol pads that are individually wrapped !! That's what I use to take the marks off !! For some reason they work much better than the bottled alcohol !! They are stronger I think !!