I have a 1/4 foot on my machine. I move the needle over to the right just enough so that my blocks come out to exactly the size i need them to be. Before I moved my needle over it seemed that some of my blocks would be just 1/8 inch shy of the right size. Now if they are a little off it will be a tiny bit too big and then I can trim it away if I want.

When working on small projects it helps if they are all the same size and that some are not 1/8 inch too small.

My understanding is that the "scant" 1/4" seam allowance works because the "turn of the cloth"- fold takes up a small amount. If the seam allowance is slightly less than 1/4" the finished block will be closer to the actual size block one is trying to accomplish!

I think the "issue" starts with the size of the cut pieces.

For example: even though I think I cut "exactly" - when I measure my 2-1/2 inch strip - it is actually about 2-9/32 inches wide - about a rotary blade's thickness wider than the template.

So I can use a "regular" 1/4 inch seam - and when sewing non-bias edges together - the unit usually ends up being the size I am aiming at. There is enough "extra" in the way I cut to allow for the thread thickness and the amount of fabric taken in the turn/fold.

If my cut pieces were EXACTLY 2-1/2 inches, then if I used an EXACT 1/4 inch seam, there would be some "loss" when I pressed the unit - the fabric has to turn and accommodate the thread - and the result would be less than 4.5 inches - as Dunster said.



I think the place to start is to measure the size of one's cut pieces. A couple of threads here and there can make a difference in the finished size of the unit.

1/32 of an inch is not very much - but say the block is made 12 strips that are cut at 1.5 inches.

If one loses (or gains) 1/32 on each side of the strip - that would be 1/16 of an inch on each strip - and there are 12 strips

12*1/16 = 12/16 = 3/4 of an inch.

The variance can be cumulative - If one was planning to alternate plain squares with the stripy units - it could be a bit of a problem.

(Although I did see "somewhere" - to make the units of the smaller pieces first - and then cut the bigger units "to fit")

This is why I love die cuts. 99% of my cutting is with a Go. Every piece is exactly the same. I can tell immediately if my seam allowance is off. If there is a measurement I don't have for a quilt pattern I have a custom die made. I haven't found that many quilt patterns there isn't a die for, maybe a different size block so I make more or less of them. I seldom use my rotary cutter unless I'm using a specialty ruler.

I think putting the focus on the measurement of the seam allowance is what confuses people. It doesn't matter what the measurement of the seam allowance is. What matters is the size of the finished block. The question to ask is, 'What seam allowance is going to result in the block being the size it is supposed to be?"

You have to experiment to see where to set it on a particular machine. Someone recently posted a video that suggested cutting a nine inch strip of fabric, and then cutting nine 1 1/2" strips of fabric, sewing the 1 1/2" strips of fabric together, comparing that length to the 9" strip, and adjusting the seam allowance until the sewn strip matches the 9" strip. Whatever that turns out to be, that's your 'scant 1/4" seam allowance'.

Because, as has occasionally been pointed out to me, i am an OCD control freak!!! :p Seriously....i should have clarified....i never know if i am going to hand stitch or machine stitch my Dresdens or other 360 degree wedge patterns....and i do love hand stitching Dresdens.......so when i cut them out, i just mark the seam and i'm good to go either way. Also...i find i can machine stitch faster along the pencil line than when i use the tape as a 1/4" guard/guide.

I agree 100% with this Dunster....but i was referring to my own designs/block combos....not purchased patterns nor swap blocks....which would absolutely be a mess if you used your own seam allowance. But when i am making my own, i make allowance (no pun intended) for the different types of blocks before hand.

If it makes you feel any better, I have been quilting since 1992, and I have yet to achieve a quarter inch seam. I am just happy they go together and look okay when finished. This does preclude me joining exchanges, but am okay with that.

I sure try very hard to do a straight 1/4 inch seam:) Each time the subject of the "scant 1/4" comes up, it makes me nervous. I don't know why I read it! Anyhow, to each his own and I will never be perfect:) But I sure enjoy the things that I make. You all go for it and enjoy!