Probably a dumb question but I have a hard time mastering a scant quarter inch seam but no problem with a "true" quarter inch. My 1/4" foot is accurate. As long as all my seams are equal why should there be a problem?
Just asking.

Sewing on the 1/4" line and pressing the seam over loses a scant amount on the pattern. For some, that leaves a block smaller than the expected size and when angled pieces are included, the blocks may not match perfectly.

You may find that you have to alter the lengths of sashing and borders to accomodate the difference. How much would depend on the amount of pieces in the blocks :D:D:D

if, after assembling your blocks, they measure to the correct finished size, then you don't have to alter anything you are now doing.

Can you move your needle over to the right a bit? I also use a thin thread (So Fine)

I've never used a scant quarter inch seam in my life and have never had any problem at all with things lining up or matching or being out of square. If the seams are all the same, you'll be fine and the only difference might be a slightly smaller quilt than the pattern says. Why make it harder than it is?

A good friend gave me some very good advice: When you strip cut, as long as you keep the seam consistant everything should come out fine; however, if you are using templetes to cut the pieces and the pattern calls for "scant" 1/4 inch, you must do the scant or the pieces will not fit together.

I don't understand why any pattern would call for a "scant" 1/4 inch. How can you measure that? As for losing a bit when you iron to one side, why not just iron the seams open. I open them on quilts with a lot of seams to avoid too much bulk in the seams and have not had a problem with lining up blocks.

Can you move the needle sideways a little bit on your machine? That works for me.

Sometimes the problem arises from the fabrics being different thickness or stiffness. The fold is different. Think scrappy memory quilt made from clothing - dress shirt vs work shirt.

I found that if I am REALLY, REALLY careful at every single stage I CAN get a scant 1/4" seam. But you know what? I ain't havin' no fun that way. So I decided to try to pick patterns that I can cut down to size or where the scant 1/4" won't be essential.

My 1/4" seams are better than they used to be. And maybe someday I'll get it. But in the meantime, I just wanna have fun and I don't intend to stress over it.