I went with the duck/canvas striped fabric the first time and it did get dirty back when I used spray starch. I no longer use spray starch now. I found some of the heat resistant silver fabric in my stash so that's what I use now but I stapled it on the underside so no two sides to flip over. Luckily I had this fabric on my pressing station when my old $1 iron caught fire as a couple of flares dropped onto the silver fabric and only put a hole into the fabric and didn't continue burning anything else in it's path. I was also lucky that it happened while I was there and not away from the pressing station as it could have been a worse case scenario for me. I had left the iron on for a couple days as it was one of those that didn't turn off automatically. But boy could it press out the wrinkles. But since then as I tend to forget to turn things off when I'm going back and forth between the cutting table, sewing machine and pressing station, I now have an iron that will turn off automatically if left alone for too long.
The silver fabric doesn't seem to get as dirty as regular fabric does. And even though I have a couple tiny burn holes in mine now after that fiasco, I can still use it.