This video will help you make a mat support for your Cricut. Especially helpful if you work with the 12 x 24 mats like I do. Below is a link to a PDF document that contains all the information you need, supplies, instructions and cutting layout. I do not know if this will become clickable when I post or not. If not just copy and paste. If you have any problems let me know. Please forgive any flubs during video, I am not a professional at this. Good luck.
https://drive.google.com/file/d/1LgRHCj4xswoWoWAlgd5EG9xappYQdzkv/view?usp=drive_link
Correction #1 - I used my decorated mat for the first time this am and found the long mat caught the edge of the duct tape. I put a piece of packing tape over and it fixed mine. Scotch would work also.