Setting the Seam...Why?
 

Since day one, I have always read, watched, or been told to set my seam with the iron (give it a good pressing) before pressing the seam to one side, or open. When I asked why, I've always gotten some cryptic answer in, mystic, "quiltese." I'm baffled. Would someone please give me a more scientific reason to "set my seam." Thanks.

Setting the seam from the back, then pressing it to one side from the front accomplishes two things that I've experienced: 1) It seems to "nestle" the thread into the layers of fabrics, and 2) The seam is now warmed and very pliable to send that seam to one side or the other when ironing from the right side . . . no overlaps or little tucks at the seam.

You'll find that your measurements stay very true as well.

Hope this helps.

I also think it makes the block lie flatter

I think it matters only when accuracy is really important for a quilt top. Many of the tops I make are the fast and easy type where absolute accuracy has little to do with outcome -- patterns such as "Falling Charms" from the Missouri Quilt Company, for example. Fast and furious works fine for those types of patterns where you don't have to match triangles to squares, etc.

I think it always looks nicer when setting the seams. The seams also line up better.

It is one of those things that you do, not really sure why, but the seams do lay nicely.

You know how sometimes you run your fingernail down a seam to ease the sense of 'gathering' or along a fold of a piece of paper because it makes it "sharper"? That's why I "set the seam" before pressing the block/strip open. Just makes it look a bit neater and easier to abut the seams when joining to another section or clock. :)

Jan in VA

You can try this. Sew 2 patches together, now just unsew them by clipping the stitches from one side or the other. Should be pretty easy to grab the stitches with your seam ripper. Now sew them together again, and this time set the seam. If you try and unpick the seam it will be more difficult because the thread has embedded itself into the fabric a bit.

I quit setting seams. I have made several hundred square in a square blocks. The second and fourth triangle added just never laid as flat as the first and the third. I never could figure out why. Then one time I just put the first triangles on and pressed them open before I put the second triangle on. That time the second triangles laid as flat as the first ones. The difference is the first ones didn't get set and because the second triangles were already on and got set when I pressed the first ones open.

All great answers. And, the quilt is completely square when you are finished setting all the blocks together. That makes a big difference in the quilt after it is washed or as a matter of fact, quilting it or putting on the binding.

I have skipped the step of ironing the seams to one side, and it was more difficult putting the quilt together. I advise you do it. Looks better in the long run.

OK...I might buy this theory. Perhaps when you do that first pressing to, "set the seam," it slightly shrinks the thread and smoothes out any gathering that has occurred due to thread tension, etc. But, why can't you just do that with one motion of pressing the seam to the one side instead?

Wonderful, clever idea for "proving the point", PaperPrincess!

Sometimes I set the seams, sometimes I don't. I can't tell the difference. Some quilt pros don't set seams either.

I think "quilt pros" set a seam if and when another piece of the block, or another seam is going to be attached to it, just makes for more accurate piecing. At least it works that way for me.

Why? Because I'm the mommy! In garment sewing I was advised to set the seam if a long seam looked puckered. The setting took out the stretchiness. That could carry over to a much shorter seam, even if you do not actually see that it has stretched a bit. I actually do it both ways, expecially if it is on the bias. This may be one for Myth Busters.

I think it makes my seam lay flatter since the thread is embedded in the fabric. It may seem like more work to set the seam but it really is not since you already have the iron above the fabric. Pretty easy to QUICKLY press seam flat, turn fabric over and press seam to side from the right side of the fabric. I do not press seam open since I do not like to burn my fingers. Remember there are no quilt police!!!!

*when I did not know,,, I did not set the seams*,,,,. NOW I do..lol . I have advanced and my quilts are thanking me, they are proud to be shown off and that makes me happy. HUGS

If you set the seam on the side you want the seam to fold to, the seam will fold automatically to that side when the piece is opened. That's the only reason I set the seam.

I'm sorry, I disagree. Accuracy is always really important for a quilt top. Even if all you're doing is sewing 10½" squares together, setting the seams makes the block size more accurate, more uniform, and therefore the top is more square, and the whole thing looks better when you're done.

I suggest the OP make two four block 'tops' - one made without setting the seams and one made with set seams throughout. She can then decide if she thinks it's worth doing. It's a personal decision.

I do it when I think about it and am not in a hurry. I think it does help the seam lay flatter, but you do end up pressing the same seam twice, which can be time consuming, so it's not the end of the world if you don't set the seam.

I don't think setting the seam before pressing to one side really doesn't do anything, so I don't do it. I think the threads will get buried in well with just the one pressing. It just seems like a waste of time and electricity to me.

Setting a seam or melding is one of those seemingly tedious things sewers do but it does have a purpose. Ages ago when teaching garment sewing it was explained to every seamstress as multi purpose.

1. The stitching you do has height over the two pieces of fabric that are sewn together due to the fact the thread is round and sitting on top of the fabric. By pressing BEFORE you press open or to a side it allows the bulk to be presed flat giving you a cleaner sharper place for the seam to fold. You will not achieve the same clean fold by consolidating the two steps. The smaller the piecing, the tighter the corners the more critical this step is in garments and in quilts.

2. Any micro gathers from the feed dogs can also be pressed smooth giving you an accurate finished surface for further work or piecing.

3. It makes pressing to one side or open easier to accomplish once the excess bulk is smoothed out allowing for a better flat pressing technique.

4. It refreshes the starching giving you a easier to work with product.

5. your seams will be sharper allowing for better accuracy in matching seams for joining pieces. An error up to 1/16 perpetuated in each block in a crib quilt will completely screw with your final work tring to get everything to line up.

as a clothing judge it was always obvious which did and didnt meld their seams. I am guessing it would be the same for quilts.

Wow! Hot topic! Thanks for everyone's opinions. BTW, I do set my seams...well, most of the time. But, only because I think it will be easier to press to the side the second time and lay just a tiny tad bit flatter...just a tiny tad...maybe a 128th of an inch. I know, all those fractions do add up in the end, but I don't sweat that small of an amount. Sometimes I don't set the seam, because I'm afraid of stretching that seam line during all those pressings, especially when it's on the bias.

IMHO, "embedding the stitches," is just a bunch of mumbo jumbo. (Sorry, I don't mean to offend anyone, but that term just doesn't mean anything to me...it's cryptic.) Physically speaking, the stitches don't embed themselves, so the scientist in me just won't buy that one. The thread may lie flatter, it may shrink, or stretch a little from the heat, but embed...nope...I don't think so. Just my opinion.

LOL...Oh, Phyllis...I like your style! Yes! Let's send this one to the Myth busters!!! Another urban (err...shall I say...suburban legend) to be tested and possibly busted!

Have enjoyed the discussion and agree that the thread does push the fabric up just a tad and setting it makes the thread flat instead of round and thus lies flatter. (Tropit, you're right, it doesn't embed). This is one reason of two or three why I don't like to watch Ludlow quilting. She doesn't set or press (ever) And you really can see the difference if you're accustomed to seeing set seams.

I don't know that I have a "scientific" reason that would satisfy. Sometimes I set the seams, sometimes I don't, it just depends on the pattern and each individual seam. I find that bias-cut pieces lay MUCH better if I set the seam before pressing the allowances to one side.

I can understand if an analytic mind rejects the term embeds, there are better words, but the essence remains of what is going on. The threads in fabric have quite a bit of airspace between them, and then when you stitch the sewing thread lays on top of that. The first pressing, or setting, or meld allows you to use direct pressure on the three components to get the flattest most compressed seam area. In essence it is not only compressing the threads and fabric but also embedding the thread down into the fabric where fluff (air) used to be. You do not get as good a result by only pressing the seam open or to the side as you have more layers to be directing the force(pressure) and heat of you and the iron through to get the same effect.

Its like cooking with grandma when you have a degree in chemical physics. Some words just make no sense....

I learned to sew in the 60's and no one told me I was to embed the threads first before pressing the seam open. I wonder if my projects would have been much better if I had known. Now that I know it is good to do, I always set my seam before pressing to the side or open.

I agree with Jo. I really didn't like to press when I first started sewing. I thought it took up too much time, but after years of sewing, I found that pressing as you go keeps the material neater and you end up with a more professional look.
One of my bad habits was saying to myself just get it done. Now, when I get a seam that is not going as straight as I know it should be, I have to say to myself. STOP, go back and do it right. lol I say that a lot.
Syl

Always wondered about this also - thanks Dolphyngyrl for asking the question and to all those who replied.

Ok I'm going to sound like a complete dummy here, but I do not understand the term "set your seam". Press open or press to the side is all I've ever encountered.

Setting the seam is pressing the seam as it comes out of the machine. Just take the pieces out of the machine, don't open or do anything but press along the seam. Then press open or to one side.

I find when I set the seams, it makes them nice and flat and when I press from the front, I don't get any unwanted pleats. Remember, "press", not iron.

Oh. I've always finger pressed my seams either open or to the side immediately, then taken the whole lot to the ironing board for actual pressing before going to the next step. Wonder if that counts!?!

Just makes everything look nicer and helps blocks come together. If you don't set the seam those areas will have a raised divide look to them.

Then you are skipping the step "pressing the seam", which is the subject of this discussion.

Pressing the seam prepares it for the 'folding over' of the seam that you get when you press it to one side. Overall, it gives you a neater looking and more accurate set of piecing.

I don't have a scientific explanation, but I've learned by reading all the response's. Great lesson learned.