If I'm cutting through 3-4 layers of fabric, I use my 60mm. Other than that, I use my 45. I have one marked for paper. I also have the big old fashioned paper cutter with the huge blade on the side. I have that in one spot on my bench where my cutters sit. So heavy. I also buy them on sale when notions are 50% or if I have coupons. I purchased the blade sharpener and sent it right back. Worthless! Also cleaning the blade helps last longer. Lint gets caught up in it and feels like the blade doesn't want to turn. I also close after cutting. I reached for an item once and nicked my finger. Luckily it was not on fabric. Bandaid and antibiotic cream was all. When I buy blades on sale, I check for rust. Yep, I've taken them back because of rusty blades. I keep a magnifying glass in my purse now to see if there is any rust. I bring it to the managers attention.