Probaby shouldn't say this, I used to work at Joanns. I found they were kind of flimsy IMHO. I got the steel frame shelves that "Stack" (with brackets etc) - see picture - at Menards. Similar ones at Home Depot, Lowe's etc. They come with really nice thick wood for the shelves - you pick height.
If you have 3 shelves high, makes the PERFECT height for an industrial strength cutting table. The biggest Olfa mat covers 90% of the top. Plus, you will have 2 shelves for books or storage underneath. A much better buy. I did this for an "iron board" (with portable iron surface on top) and for a cutting table. Good luck.