We are constantly experimenting with new glass colors, always looking for the next one to add to our line of color.  When we make a test batch that looks promising we list it for sale here and wait to hear what you think.  If we get a lot of positive feedback on a test batch then we’ll try it again, checking that it is reproducible and that the feedback is still positive.  If all goes well then it becomes one of our regular production colors.  If you are looking for information on previous test batches or to leave a review for any of them, go to our Color Archives page.  All of our test batches  are tested compatible with Effetre Clear.