I'm a 45 mm cutter, and use an Olfa. I'm not strong enough to cut through multiple layers, and if my Olfa isn't cutting, it needs a new blade. I'm thinking about getting the smaller one for smaller cutting chores. We'll see.

I'm with you. Cutting through several layers of fabric is real easy.

What mm is the small one - about an inch or a tad more? I need blades, but not sure what size. I bought 2 different Olfa's at a yard sale and know the large one's size, but not the small one.

45 blades are everywhere......60 not as easy to find blades everywhere ....

I use the 60, just like it best.

Unless you're cutting lots of layers, the 45 degree is the way to go. The replacement blades on the 60 are a lot more expensive too.

There are 25.4mm in an inch.