First things first.
Getting an accurate 1/4" seam allowance.
You must have an accurate seam allowance! How to test? Cut three strips of fabric 2" wide. Sew the three strips with what you think is your 1/4" mark on your sewing machine.
Press the seams of the strips in one direction.
Now measure them. They should measure 5" across with the center piece measuring 1 1/2". If the set is smaller or larger, move your 1/4" mark and try again until it is right!
Remember that pressing in one direction also takes up some fabric.
I put masking tape on my machine to guide me. Just follow the
steps below.
I can put some pressure on the fabric on the bottom so the feed dogs don't eat it up and it ripples underneath.
More fabric underneath than on top is a big problem when sewing strips together.
.
You can also use a ruler. Put the 1/4" mark from the ruler
under the needle.
I put "check needle" on the tape. Why? If I put my needle in the center position on my Bernina, the feed dogs stick out beyond the pressure foot and I can't put tape on there because the tape will cover the feed dogs. So, if I move my needle over on click to the right, I am clear of the feed dogs with my tape.
Okay, now if I turn off my sewing machine and come back later and turn it back on, my needle will be in the center again not one click to the right. I will start to sew and forget about moving the needle... I will sew four strips before I realize that the needle is in the wrong place and my seams are way too big! How do I know... been there, don't that! I hate to rip so I remind myself to check the needle!
Okay, now I can just place my fabric right up to the tape and sew my little heart out and I know I have a 1/4" seam because I tested it.
