Good afternoon, MuseumLers - As a textile/costume conservator with a textile science background, I do not have an issue either with a bit of polyester in the sheets (up to 40%). The polyester/cotton is usually blended together as a fibre in to the thread that is used for the warp and weft. In fact, it is a good idea for those situations where the relative humidity is not well controlled (ie most historic houses). You do not want to use sheets that have a perma-press/no iron finish on them as those finishes are formaldehyde based and do not age well. The smoothness of the weave of the sheet is important as you do not want a rough texture imprinting on your artifact - so usually I recommend at least a 400 thread count if it is a plain weave sheet. Satin or sateen weave sheets are very useable too. White sheets = no potential dyes/pigments bleeding or crocking to worry about. White also lets you use the shrouds/ coverings as the "canaries" because the markings due to "grubby paws", placed on an unwiped dusty table and "dragged on the floor", etc. show up so nicely in contrast. Please feel free to contact me off-line if you need further clarification or have additional questions. Regards, Meg . _ _ _ _ _ _ _ _ _ ___________ Margaret E. Geiss-Mooney Textile/Costume Conservator & Collections Management Consultant Professional Associate - AIC 707-763-8694 [log in to unmask] ..As a conservator I have no issue with a bit of polyester in the sheets. I'm more concerned that the sheets are colourfast (i.e., that they colour does not run when they get wet) & that you wash all of the bleach out of the sheets.... >...Why is a little polyester not good for garments?... > >... Be very careful that any sheets you get are 100% cotton. Most sheets > these days have some polyester in the blend which is not good for your > garments.... ========================================================= Important Subscriber Information: The Museum-L FAQ file is located at http://www.finalchapter.com/museum-l-faq/ . You may obtain detailed information about the listserv commands by sending a one line e-mail message to [log in to unmask] . The body of the message should read "help" (without the quotes). If you decide to leave Museum-L, please send a one line e-mail message to [log in to unmask] . The body of the message should read "Signoff Museum-L" (without the quotes).