Originally Posted by gal288
The fabric is not on grain, it's that simple. I have always realigned the fabric, never use it the way it comes off the bolt.
Unfold the fabric,, press out the center, hold the 2 selvages edges together, move the fabric left or right untill there is no distortion in the folded edge. There will be bumbs & bubbles in the fold when it is not straight, but as soon as the grain is aligned, the fabric will lay smooth.
I then lay it on the ironning board, press from selvage edge to fold, being sure to keep selvages together. If you get a bubble when pressing, it's still not onn grain.
Have done this method for over 40years & it works, just a little practice to learn.
Good luck
This is what I do also. I used to end up with those curves all the time until I got my fabric aligned correctly by doing the above method. You can really see this if you shift the fabric back and forth while looking at the folded edge. It soon becomes obvious when it is aligned and when it isn't. Try it and you'll see.