This sampler consists of the blackest black I could find, and a UV reflective white cotton. I conducted a simple test, by collecting a variety of whites and shining a UV bulb onto them to see which would glow.
This sampler is part of a large design that was intended to be viewed under UV. I abandoned this sample though as I quickly realised that the design was too intricate for the small number of warps. I will rethink the dimensions and work out the correct scale once I have more experience and come back to this design later.