The mat will be soft and be like new again.
Cutting mat has grooves.
Soak the mat in room temp water for about and hour let dry.
It reminds me of a c filter material there is a trick to removing all of the fabric particles from the cuts in the mat.
Reset the mat borders for the desired spacing of the v groove from the mat opening.
A v grove provides an accent line around the outside of a mat opening giving an effect similar to the ruled lines on a french mat.
I have one old mat soaking now.
I just gently bend the cutting mat over the edge of the table or over a coffee can.
When the moisture is gone the mat dries out and will have cut marks and dull your blade.
Cut the artwork opening in the normal fashion with the mat face in.
Remove the mat and place it back in the machine face out.
To clean the fabric whiskers from my rotary cutting mat i dry scrub it with a greenie which is really designed for scrubbing dishes.
It might not seem like a big deal at first but over time all these grooves add up and can affect your cutting accuracy or worse snag your fabric.
If you have a self healing cutting mat it needs to be re hydrated to stay self healing.
That s all you have to.
When you use a rotary blade on a hard plastic cutting mat you leave a small groove in.