Basically, they are both the same. If one is from a name brand supplier, such as Rohm and Hauss or Dupont, it usually is masked with brown paper with their logo and it will be more expensive. Most of the cheaper acrylics are either filmed with blue transparent skin or plain brown paper and are imported. Some of the outlet stores may sell Lexan, which is used in glazing, is considered bullet proof in its thicker grades and although it looks the same, it is chemically different. You can tell the difference by tapping on it with your knuckle. It will make a tinny sound as compared with regular acrylic. As far as an online supplier, I know of one company named Glasscages.com. They will cut to size in various thicknesses. I purchased an acrylic tank from them once. Not the best as far as appearance, but it served the purpose.
