We realize you have many choices when deciding on a protective sleeve for your treasured record collection. It can be confusing which product to buy, especially for the 1st time buyer. Here?s a quick reference to make sure you know exactly what you?re getting when you buy this Collector Protector Album Sleeve. Sleeves come in varying materials and thicknesses. BOPP Poly bags (these bags) are shiny and extremely clear. They are more stiff/rigid thus they hold their shape and are less prone to wrinkling or fingernail indentions than softer material such as CPP, LDPE, HDPE or regular polyethylene. All these other bags, even standard polypropylene bags have a haze to them whereas the BOPP bags don't. These bags are thinner and less pliable than the softer bags which means they will split at the seams easier. However, careful handling will prevent most of these splits, especially if you load the album cover straight in and not angled. BOPP film sleeves have a maximum thickness of 2 mil, whereas other bags can be manufactured in thicknesses above 2 mil. Our bags hold their clarity longer than ethylene-based bags which tend to become more milky or yellow over time. Don?t be confused between transparent and translucent. Our bags are transparent, like a window pane. Due to their make-up, our bags provide a better barrier to outside elements than the PE bags, they resist mold & mildew and they are recyclable. Overall, if you want to make your covers look the best they can, while providing great protection, you?ll be happy with this product. Thanks for your interest in our sleeve. We are happy with it, and hope you will be too.