Frankly I find most tubes to be questionable when they're made from commercial products. You want to use a commercial font in your art work? Buy the damn font! Don't go downloading tubes of commercial fonts that you haven't paid for and don't MAKE tubes of commercial items you've paid for and sell or give them away to others. That's my take. Take it or leave it. 

It is a miracle that curiosity survives formal education. - Albert Einstein