Lightfastness test

I want to use only top quality materials so I can offer my clients/collectors only the best possible artwork that I can. I did a lightfastness test with some of my gouache paints- it's been a year- I painted 3 "swatches" of each color, labeled them (the ink disappeared on the labeling of the 2 that were exposed to the sun). One was painted only, one was painted and sprayed with a spray that was supposed to help protect against UV rays, and the 3rd was covered. I am amazed at the results. They really held well. The more major change was the lemon yellow which turned to more of a light ochre. The mauve (purple) lightened a tiny bit, and the sprayed rose lightened a bit! The unsprayed rose lightened a tiny bit, but less than the "protected" sprayed one! The rest of the colors held very well. This was direct sun exposure for over a year (to make up for some rainy/cloudy days)! You should never, ever put artwork exposed to direct sun, or even indirect (bounced off a wall for example- I learned that the hard way unfortunately, didn't even think about it). So I will feel confident when I use these paints. I intend to do the same test with my acrylics and caseins just for fun, but that will take another year!!!
Thought you might all like to see the results. The colors may not be totally true/perfect to what they really are- I did the best I could quickly, but every computer is different too. But you can see that there is very little change. It's a simple test for other artists to do and for collectors it's nice for them to feel that the work they purchase is as top quality as possible. This is more than a lifetime investment- it is hopefully an heirloom they can pass down for their future generations to enjoy as well.