It all depends on how it is done. Collage artists recycle, its part of the meshing of textures and patterns. One thing I have been doing lately that I personally think is OK and feel free to fill me in if you see any horrible red flags going up. I combine the labels from craft beer bottles (sometimes wine bottles as well) with hand made papers, ripped and painted and formed into the shape of whatever glass that particular type of beer would be served in. If you are familiar with it, you could probably figure what type and brand it is, but its not like I put the label on and framed it, it was used in combination with my papers for color and line and contrast and well-- a little humor... I think it would be worse if I started photocopying the labels. This is the real deal, I pay the company for each and every label I use. The money I charge is for my labor in making the art. I don't believe there can be a black and white rule here. The artist needs to know that the focal point has to be their own creation. I do not think that you can totally outlaw taking something already existing and working into it and making it something else. That too can be art, if you start getting too exclusive than I can write off 25% of booths at most art fairs as "no no's if that's the case... I am not saying there are not sleazy people/artists out there that take the lazy way out, no doubt but please don't group hard working collage artist with them just because we utilize recycled materials sometimes. Thanks ;)