I still think one of the better ways to achieve accuracy is to do the "strip test" to see how one is doing as far as achieving accuracy. There are several factors to consider when attempting to achieve the desired size of the unit or block.

It also is worth the effort when changing fabrics, thread, presser feet rulers, - some fabrics have a lot more heft than others. What may get the hoped for result one time, may get a different result when one changes one of the other factors.

There are lots of great ideas here. I have one more. If you are cutting a lot of identical pieces -- once you have found the right place on the line -- mark it with a piece of tape. Put the tape along the appropriate line on the rules and use it as your cutting line. I use a short piece of painter's tape cause it comes off easily, can be reused and leaves no residue.

By marking your line with tape, you won't have to figure out where you want to position the ruler each time you move it. I read this idea years ago and have been very successful with it.

I learned to cut fabric and wood a fraction over the line on the ruler, just like pencil drawings, cutting wood/timber etc, and using a saw, we must allow for the width of the blade. I also use a proper 1/4" foot on my Brother machine with a guide to the right so that fabric sits against the guide as it feeds through.

I haven't read all of the responses so hope I'm not repeating ; I would get a 1/4" foot AND use a stack of post-its (I do mean a stack at least 1/4" high). I use Olfa cutting mats and rulers and have found I need to measure from the fat lines. Make sure your rulers and mats measurements are the same; using the same brand is a help, if not possible lay your ruler on your mat and see if they match in inches. If your machine has the option of moving the needle to the right or left, do some practice seams and see what needle setting gives you the accurate 1/4". I have to move my needle over 2 positions to the right even using the 1/4" foot.

I used to use the Omni grid rulers, but have found that the frosted Olfa rulers are actually much better. They have dashes as lines, so you can see the edge of the fabric very clearly.

It is the measurement between the seams that really matters.

I have found that if you have several seams in a block it is important to maintain the scant 1/4 seam. Also, in a class on precision piecing, the instructor recommend two things when using the rulers. Always use the same brand and line up with the larger side of the line.

I've read to cut on the right side of the line--the side the rotary blade is on. If anything it gives a smidgeon of an exra thread or so.

I'm finding that using a foot like that I still need to select the 1/4" foot menu and then move the needle to the right a couple of spaces.

I was using the foot with the little piece of metal hanging down. In hindsight, I think I was jamming the fabric up agains that too much, causing a slightly larger seam. When I changed to a 1/4 inch foot without out that metal piece hanging down....a clear foot so I could see through it, I found out that worked much better for me.

Maybe you are doing a similar thing? Or maybe you just need more practice. (I needed more practice also. I was pretty impatient with myself, expecting to conquer the 1/4 inch seam quickly because I had been a seamstress all my life, but I had never even thought of a seam smaller than 5/8 inch. I was just very impatient with myself.)

Dina[/QUOTE]

So true. Once you figure out the cutting, then work on the three strip practice piece and measure the center to see if it is what it should be.