Scant quarter of an inch
 

I hear and read about this all the time. We are also told to do 1/4" seams.

What is the difference and why do we need to do scant 1/4" ? How scant do we do 3/16 or 2/16 so confusing.

will a pattern size be affected by always doing 1/4" rather than a scant?

where did the scant 1/4" come from?

help I'm so confused.

Scant 1/4" is confusing to me also. I have heard so many discussing the difference, but what difference does it make? If all seams are the same size, the blocks will all be the same, right?

I agree with the consistency of seam measurement vs making yourself nuts about trying to achieve a 'scant' anything. Scant is (at least my understanding) a couple threads shy of 1/4". Why??? If your pattern needs to be that precise - use paper piecing (mariner's compass type comes to mind). Otherwise, for me, as long as my seams are consistent and things fit together correctly, I'm good with it!

I have done scat 1/4" seams when doing very small minature quilts. It just leaves a tiny bit less bulk on the seam allowances.

Well, I get an error this morning on the search function but I'm pretty sure we have had several recent discussions on this - there are some methods for getting this, and some folks don't worry about it. I don't but then again I rarely make anything that isn't strips or squares or half square triangles. They all seem to work with a 1/4 inch seam.

I also hear talk about this a lot - and apparently if a pattern calls for it, you are in trouble if you don't do it right. For me.....life is just way too short for this kind of stress. Just MHO.

I believe, as i have done it for many years, that as long as you use the SAME seam allowance for the entire piecing process, that's what matters. I have never used a purchased pattern - just make my own from blocks i like - and I use the edge of my presser foot as my seam guide - it gives me a 3/8" seam.

There is one caveat to this......Dresden plate....or any of the patterns that form a "circle" out of wedges - because you have to keep the 360 degrees correct or it will fail.....in those cases i mark the 1/4" seam line with a light pencil and stitch on the line...goes quickly and accurately.

Rather than drawing a seam line on the fabric to get your 1/4" why not put a strip of masking tape or something on the machine bed 1/4"away from your needle to give you the right measurement, then you could do all of your piecing with the recommended seam allowance.....

Being consistent is sometimes enough, but not always. If you're doing a quilt consisting entirely of 9-patch blocks, for instance, you will be fine with any size seam allowance. However once you start mixing in angles or blocks that have different numbers of seams, you need to patches that measure correctly in order to have the whole thing come together accurately. Quilt patterns are designed with a 1/4" seam in mind, but the theory underlying this is that you're living in a 2-dimensional world. However, fabric and thread are not 2-dimensional; they have some thickness. When you take two patches that are 2" square and sew them together with a seam that is exactly 1/4" you hope to wind up with a rectangle that is exactly 2" x 3.5" (losing 1/4" of each 2" square in the seam). However you are going to wind up instead with a rectangle that is 2" x something less than 3.5". How much less will depend on the thickness of your fabric and thread, because these things cause some of the fabric to be "lost" in the seam. This is why the "scant" 1/4" is important, and how scant depends on the thickness of your fabric and thread and how well you can press the seam flat (which again depends on the fabric and thread).

Even if there were no need for a "scant" 1/4", being consistent is not enough when you are dealing with more complicated blocks. Suppose you decide to sew 1/2" seams instead of 1/4". If you make a 9-patch it looks fine. If you make a 4-patch it also looks fine. But now take a 9-patch and a 4-patch that were supposed to be the same finished size and try to put them together. It won't work, because there are 2 seams going down the 9-patch and only one seam going down the 2-patch! This is an exaggeration, but the theory holds even if your seams are only 1/16" too large or too small.

The lesson to take from this is that you need to measure your block as it is formed to be sure your units are measuring correctly. The seam size needs to be adjusted so that the *finished* patch is the right size.

Block pattern measurements are given for 1/4" seams. It's the standard size for quilt seams. If your seam is bigger or smaller the block will not measure the size as the pattern states. A scant won't make that much difference but each seam has to be the same either a scant or 1/4". Thread weight plays a big part of the scant and full 1/4" seam.

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!

EXACTLY!! You lose the tiniest bit of measure with that fold, and it all adds up! And the more seams you have in a block, the more it will matter on the finished size. That scant bit you subtract from your seam allowance makes up that difference so that you'll have a perfect ending size block.

2 9/32 inch is actually closer to 2 1/4 inch. If you are working with 2 1/2 inches, that is 2 16/32 inches. So a 32nd inch larger is 2 17/32.
You would think thread doesn't take up any space, but look how it piles up on a spool. And folding takes a little space, too. I aim for pieces a little larger and trim segments of the block as they are made. If I'm making a 12 1/2 in. pin wheel, I need 4 HSTs. After they are sewn, I trim them to exactly 4 1/2 inches. Then one more seam each way, and I have a 12 1/2 inch block.
Trimming smaller segments of the block makes things come together accurately.
I know some of you can do your seams perfectly the first time, but not this chick.

I was not a quilter, but a sewer so I took a class for six weeks to learn how to piece a quilt. I made a queen size quilt in six months from start to complete finish on my home sewing machine. The teacher taught us to use a scant 1/4 seam and it killed me. I was used to 5/8 seams and that scant 1/4 seam was a killer for me. I ripped out every single thing I sewed because when the block was finished, it was too small. The scant 1/4 seam does make a difference because when you press your seam, it takes up room. I had to move my needle over to get that scant 1/4 seam but then I would turn off the machine and it would go back to normal needle position, so I finally learned how to do that scant 1/4 seam. I have no clue where it came from but I do know that on my vintage quilt tops, they used the scant 1/4 seam too so it has been around quite a while. It definitely affects the block, measure yours and you will see the difference.

Scant - much to do about nothing. Unless you are exchanging blocks. Quilting for me is suppose to be fun and relaxing. "Scant" is neither, I have never had a quilt that I was not able to adjust with a baggy bottom cure.

I understand the scant 1/4 will give you a truer 1/4 when the fabric is turned and pressed. Ditto to Dunster's post

Scant quarter of an inch
 

I use my pressure foot for 1/4 of an inch and instead of quilting by the side of the foot, I quilt by an imaginary line in the middle of the foot. This has always worked for me.

I do strive for the "perfect" (?) 1/4" seam, and I'm usually OK with making the block come out the right size. However, I attended a lecture by Mary Ellen Hopkins years ago who told us that we should use what works for us, using a 1/4" foot on the machine, moving the needle, etc., etc. and she called it our "Personal Private Measurement" or something similar, she does mention it in her books. I learned a valuable lesson in the 1/4" seam when a friend and myself worked together to make an Oceans Wave quilt for the church raffle quilt that year. She did one section of the block and I did another. Well, I have to tell you that our 1/4" seams were not the same, so I had to make adjustments when I was putting the blocks together. It wasn't off by much, but enough to be somewhat challenging when piecing the top together. That said, using the same machine when piecing a quilt top, makes for a happier quilter at the end of the day.

this is exactly what I was told and it makes lots of sense, especially after working on the Bonnie Hunter Celtic Soltice with a million pieces--I wasn't as careful with one set of blocks and putting them with the other set was challenging!

You are correct- I did mean to say 2-17/32 instead of 2-9/32 inch.

Anyway - my point was thst my "actual" cut size is usually a bit larger than the "theoretical" size.