In September 2018, I purchased a 24 inch North Star Polaris CT-500. I had been using a large dowel as instructed by Hsinchen Lin in his video (https://youtu.be/L3YsATFRPWU). I was finding the old hand injury prevented even thickness rolling. I also wanted to try larger slab rolled pieces.
Patterns are cut from 30 lb tar paper. It is easy to cut and can be used multiple times before a new pattern needs to be cut. I found it aids in holding the clay in place for sealing seams.
After purchasing a slab roller I discovered a build it your self slab roller located at https://www.youtube.com/watch?v=VC0QXALQT_M. It looks really cool and works based on another Youtube from a potter in Billings, MT.
The slab roller canvas can be cleaned in a bucket of warm water with a small amount of laundry or dish soap. Make sure you double or triple rinse with fresh water. The manufacture indicates the canvas can be washed in a regular washing machine on a gentle cycle. I use the bucket method because the canvas is heavily soiled with clay before I consider wash it. Clay is reported to clog drain pipes. I have not experienced it but not taking chances.
Air dry the canvas flat (no fold overs). Roll canvas when almost dry to remove wrinkles.