I purchased a surplus of these last year, and I haven't had the opportunity to use the 6-layer type. I've been storing them, and while I thought it might be difficult to sell them among the many listings, I've decided to put them up for sale. I opened them for the photos, but they are unused. According to the product description from the seller: "There may be slight variations due to being a foreign product." They feel slightly thinner than similar products from other manufacturers. There is a faint white horizontal line on the face of one sheet. I will return them to the original packaging for shipping. I hope someone who understands these points will be interested.