This morning I received a voice mail message on my phone from Mary in Texas. As I understood the message, she has been trying to emboss on some tiles and was having problems with the image scratching off. Anyway, she called for some advice, but she didn't leave her phone number so I couldn't call her back. With no other way to contact her, I am hoping that that she will see this post and for all you other faithful readers of my blog, maybe you will also find this information helpful.
Mary, I'm guess the problem is that the embossing powder on your tiles is not completely melting. This is because it takes forever to get the tile hot enough to melt the embossing powder using a heat tool. You can solve this problem by placing your tiles in the oven set to 325 degrees for about 10 minutes to melt the embossing powder. You can also use a toaster oven. If you are using your regular kitchen oven I would suggested setting your tiles on a cookie tray to keep the powder from falling onto the bottom of the oven. Since I don't have time today to make my own tutorial, here is an excellent video posted by another Stampin'Up! demonstrator, the Stamp Shack Lady, that demonstrates this technique.
You can also stamp on tiles using Staz-On ink , which creates a antiqued or shabby chic type look that is very nice. Here is video posted by Michelle Joy Wecksler, yet another SU! demo, demonstrating this technique.
Well, I hope you see this Mary and that it solves your problem. (If not, contact me at firstname.lastname@example.org.)
Best wishes to all.