Dan,
I did not see this in the MacNaughton kilt while it lived here. I do "dent" my American Heritage P/V occasionally when sitting on a solid wood or metal chair. The edge of the stage in my church's parish hall is the one that gets me the most as I will sit on the edge at one end while "directing" my students as they work on a rehearsal of an upcoming "performance". I go home with dents. I hang the kilt on its hanger on the back of the bathroom door. After the family showers the dents are well gone. The other source of dents is leaning against the tailgate of my truck when conversing with friends.
Slainte