I did try out the blades from Harbor Frieght when they were first mentioned here. The ones I got did not cut very well at all, to my disappointment. I did find the right cutting mat does make a difference in keeping the blades sharp as long as possible. The smoother the mat is, the better. I got mine at a sewing/quilt expo as a show special. It is made in USA and three web sites are available.
www.sewingemporium.com,
www.seweasyproducts.com and
[email protected]. These came off the sheet received with the mat....I do
not have any connection with this outfit except as a customer. One small concern is that the margins are kinda wide, so I extended the grid lines with a fine permanent marker. No regrets in buying this product...it even has a five year warranty.