Today I used one to press the RIGHT SIDE of a PVC strap (with the iron on a wool setting). It worked a treat! I was so impressed I took a photo. Tomorrow I'm going to try it on a COTTON setting....
Edited to add - Cotton and linen settings didn't melt the vinyl when the rajah cloth was put to the test today. Magic, I tell you....
Rajah cloths are a chemically treated cloth that somehow MAGICALLY take the sting out of a hot iron while still allowing the heat to do its work. Don't ask me how - just get one. You'll be amazed.
(Yes - we sell them. See details here).