Cutting mats are a lot like belly buttons in that way.
How to use cutting mats.
Use the numbers at the edges of the mat as a guide for the ruler to ensure your ruler is running straight across the mat.
Typically i leave a 1 4 on all sides.
Keep the mat covers.
You may choose to have your mat overlap your art while you are first learning to cut mats.
To cut a picture mat start by measuring the height and width of the picture you ll be framing as well as the frame backing board that came with your frame.
Test cut on new projects.
Then use a ruler and razor or box cutter to cut a picture mat to the same size as the frame backing board.
This leaves a nice clean white border around the art.
Use an x acto knife and a metal ruler to cut through the mat board.
Lay a clear rotary ruler over the fabric and align one edge of the ruler with a line along the mat where you want to cut across the fabric.
Keep this cover and replace it after each use to keep the mat cleaner and stickier for longer.
Cricut cutting mats come with a plastic protective cover over them.