I put clear nail polish on any "expensive" brush I own. Keep it looking new and makes me feel like it's still new for the price! Sadly, I used the OPI top coat and it rubbed off....no numbers there anymore and I wish they were still there....
well then I have very bad luck because I don't use cream products...bummer...Never used nail polish on my brushes. I know all the numbers by heart. Having said that, most of the numbers are still on despite daily washing. What makes the numbers come off is the grease from cream products, thus make sure to have dry hands when handling your brushes.