Walmart use sell June Taylor mats, the best mats in my opinion because they are hard surface. Now Fiskars is the brand sold there. Fiskars is a good self healing mat. Olfa is a good brand of mats found in most quilt shop and craft stores. Tuesday Morning stores usually have the Olfa 36" by 24" mats for $9.99. I buy one each time a new shipment comes in before the clueless employee leans them up against the shelf to sell. No use telling them why that is bad. If the store doesn't shelf them right they get a bend, don't buy one if it is displayed with a curve in it. I have mats on every flat table surface in my sewing room.

very good information given

Bigger mat and june tailor shape cut with the slots You can get the small 12"one at joanns. walmart use to carry JT but they stopped. The bigger 18" one you have to order from joanns. You can still get bigger mats from walmart. The small mats are good for small cutting

The key to making sure your cuts are straight, and you don't get that dreaded V, is to make sure your fold is even. Line the fold up on your cutting mat and THEN trim your raw edges square.

I would (and have) invest in a larger cutting mat...it makes such a difference when you don't have to move your fabric during cutting. Every time I have to move fabric I end up with an error of some sort.

i fold holding the selvedges together, then lay it down. then grab it by the folded edge and let it hang. this allows the folded sides to hang straight with each other. ... just my way of tackling the task.

If you fold your fabric, it's very important that your folds are even, and that your ruler is at a 90 degree angle from the fold.

Check every so often to make sure that your strips are still straight.

I prefer to buy 1.25 yards and cut parallel with the selvage for my long strips. I figure the strips should be on-grain in at least one direction.

Also, what QuiltnNan said - when the fabric is folded selvage to selvage - there should be no pull/fold/drape/crease lines - shift the ends until the piece is flat. (I've always had a problem knowing how to describe that - but it is THE MOST IMPORTANT step in folding fabric for cutting.)

Another tip about cutting. If you are cutting two inch strips, re cut every two cuts to straighten the edge, three inch strips, re cut to get a straight edge after every third cut, four inch strips - re straighten every fourth cut and so on. I paid good money to learn this at a very expensive quilt retreat. LOL.

I agree with misskira. I always line up the selvages, if they are straight, the strips will be cut straight. Adjust the selvages to get out any wrinkles which means you might have to re cut the sides.

While a larger mat is desirable, you can cut on a 12x12 by doing this. I do when I travel with my cutting tools. I love my June Tailor shape cutter - a ruler with slots to guide the blade, though you don't need that either if you can cut straighter than I do. Put your mat on a very stable surface, fold the fabric twice very carefully, and start cutting. Shake out the first one to see if it is straight, no V in the center and you're good to go. I've only seen one V and that was recently when I was trying to do some cutting while not feeling well. Good luck. You have what you need if you have the mat, a sharp rotary blade and a ruler over 12".