Don't believe everything you read! Sharpie's permanent markers do fade. I just checked the chips I use to identify the orchids in my collection & I can hardly read the code numbers. These drilled chips have been hanging on baskets for 6 months in driving rain storms, under hot & humid conditions, in glaring sun & have been sprayed with pesticides, fertilizers & hormones every week. Not much of a torture test. I would strongly suggest that all autographed chips in your collections signed with a Sharpie be preserved in a fitting manner as they will fade in time. Take heed & act before it's too late.