To get more wear out of your cutting mat turn it around and use the bottom half too.
Silhouette mat moving around.
I actually purchased an a3 non brand cutting mat from ebay found the tacky to be just enough.
Use your palm or even better the silhouette scraper tool to press the media to the mat and check that is is stuck evenly throughout.
My silhouette 3 is still cutting in the wrong place up on the mat at the top left even though it is set for the 12 12 cutting mat in the silhouette studio.
This can really prolong the life of your cutting mat.
Mat moving around sounds like the blue drop handle on the right is up or it is not places under the rollers quite right.
It cut in the right place one time and then reverted back to cutting in the wrong place.
Cameo mat moving around february 8 2013 by lisetteruiz i just got off the phone with silhouette and had to edit this post after getting some great help.