Hello Carmel, I use Plano lenses. I had quite a bit of difficulty sourcing the lenses. I found a few online shops that sold only to opticians and had an online form which had to be filled in giving your credentials. Here are two suppliers that will sell to me: www.mccrayoptical.com www.kleargo.com I filled out the applications as best I could, leaving some of the questions blank. McCray Optical passed me. Kleargo did not. But, I emailed them explaining what I was making and supplied a link to my website which had some images of sterling silver spectacles I already made using lenses purchased through a local optician who has since retired. After reviewing my site, they decided to sell to me. However McCray only sells domed lenses which will work fine if a circular shaped lens is required, but not on any other shape. The first pair I made with Cellulose Acetate has green round Plano lenses (with UV protection) - which I purchased from McCray. But the second pair I made, with the Blue Cellulose Acetate has rectangular lenses and require flat lenses.Kleargo sells flat Plano Lenses - but only clear ones. So I learnt how to tint and apply a UV protective coating. I purchased the tint dyes and UV protective coating from McCray. Incase you were looking to purchase some Cellulose Acetate, I found some on Ebay www.ebay.ca/itm/Tortoise-Shell-Cellulose-Acetate-Mazzucchelli-RAW-original-extruded-sheets/360879810787?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649 But have since ordered some from: www.takiron-rowland.co.jp/product/#L Takiron Rowland is a manufacturer of Cellulose Acetate in Japan - but ships out of China. I emailed them and explained I was learning how to make Cellulose Acetate spectacles, asking if they would sell me a small quantity. After a few emails back and forth they agreed. If you are interested in making some spectacles but have a hard time getting the supplies, please let me know, I might be able to help you out. Or if you would like some info on tinting lenses - I'm happy to do a tutorial for you. Nicole.