PaperPrincess

The theory is, if you are not steady with your cutter, then having the 'target' strip under the ruler protects it. If your cut is off, your piece will be cut a bit larger, so you can trim it down to the correct size.
As everyone else said, there are no quilt police, so if you are happy with your cuts, you are doing it correctly!

DogHouseMom

Does your piecing indicate you are getting accurate cuts?

I used to use my mat as a measurement, no more. I was not getting accurate cuts. I now use a two ruler method. The ruler on the left is my "cutting line" ruler. I use a "measuring ruler" on the right to measure from the edge of the fabric to the amount I want to cut - place my "cutting ruler" along the left edge of the "measuring ruler" - remove the "measuring ruler" and cut along the right edge of the "cutting ruler".

A lot of the quilts I make use small pieces. The smaller the piece, the more accuracy required (I can't ease in a 1/4" on a 1" piece, but I can easily ease in 1/4" on a 12" piece).

NJ Quilter

As others have said, there are no quilt police, so if this method works for you, then keep doing it that way. The only downside that I can see, is when the top side of your mat with the lines, wears out, you won't have the lines on the back side of the mat to use for measuring. And since the back side is perfectly usable, why not? Might then have to get used to measuring/cutting differently. Just don't start that process in the middle of a quilt. You want to use the same measuring tools/process throughout the construction process.

mom-6

For me it depends on the width of the strip I'm cutting. If it is 6" or less (the width of my 24" ruler) I have the cut edge of the fabric under my ruler at the line on the ruler for the width of my strip and cut on the right hand side of the ruler. If I'm cutting a wider strip (8" for instance) then I line up my fabric with the "0" edge line on the mat then line up the edge of my ruler at the desired width mark on the mat. And once again cut on the right hand side of my ruler.
This seems to work well for me.
Do whatever works well for you and doesn't feel awkward.

ManiacQuilter2

As long as you are accurate and are cutting SAFELY, the final results are all that counts !!

Sunnye

Where do you find these slide blocs?

AngeliaNR

I do it as you do except when I'm cutting from a narrow piece of fabric. For example, if I am cutting a two and a half inch strip from a four inch strip, I turn it so the two and a half is under my ruler. Skinny strips move sometimes. If it works for you--I say do it as you have been.

AliKat

Gads, I don't think about it much. I have a cutting cart/station that I can literally walk around. I can easily cut material without having to move it or use a rotating mat. I do have my measured strip underneath my ruler so that I accurately cut it from the rest of the material.

TerryQuilter

As long as the lines one your cutting mat are accurate, it doesn't matter which side you cut from. I cut from the left side of fabric, but that's just me--NO QUILT POLICE HERE!

MacThayer

I do it the same way you do, except that instead of using the mat to give me proper width measuring, I use a second ruler and put it over the material to the right just to make sure it's proper width. Then I move that second ruler away before I do the cutting. It works for me and gives me accurate cuts. I suggest it only if your cuts aren't accurate enough to suit you. Just make sure both rulers used are the same brand and have the same kind of lines for measuring, because two different rulers can make the cuts inaccurate. That said, if your method works for you, I wouldn't change it. We all have different ways of accomplishing the same thing, and all that matters is that it works.