Thanks for your kind email, but we do not, and never have, allowed stand-alone tubes. (If there are others making them they are not within our guidelines)  You may feel free to use Ericka's art for any non-profit websets, sig tags and etc as long as there is credit copyrighted to the artist. (Please leave a c.Ericka Baque on what you create and a link to www.ErickaBaque.com. For future reference you can refer to our site's FAQ which should answer any questions you might have. http://www.erickabaque.com/faq.html ) 

Best Wishes!

www.RatStarArts.com & www.ErickaBaque.com