Don't take off the silicone sleeve! It will break.
"I really wanted to like these, because they look very cute. However, the product description on the website and the materials that come with the product are very misleading. Both say "no need to remove the silicone sleeve. " What they do not say, and should, is that if you try to remove the silicone sleeve, the sleeve will rip, leave chunks on the glass that you can't get off, and you won't really ever be able to get it back on again. I will be using these for storage, without the sleeves. It really should say "never remove the sleeve. ""