Looking for some advice - I have a Thermarest pad that works perfectly, even after 38 years! However, it has a very smooth surface and on the slightest incline in my tent, I'm fighting the slide all night.

I'm thinking to put some silicone patches or lines across both sides, not too much so the weight doesn't make a difference. So the question is, what would be best to use (in anyone's experience) that won't damage my Thermarest, tent bottom, or sleeping bag?

Thanks ahead of time.