As quilters, we all try to produce quilt tops that lay flat, have precise intersections, and minimal shadowing. Unfortunately, when two or more seams come together at one spot in a block, a multi-seam intersection or bulge can form. We can think of these bulges as potential speed bumps because they make it more difficult for us to create smooth, precise, and eye-pleasing quilts.
As discussed in a previous post, “Ironing vs. Pressing,” one of the ways to ensure that pieced quilt tops lay flat is to firmly press all seam allowances. This seam pressing step is a good starting point for minimizing bulges but, for most block designs, subsequent actions must be taken to keep unsightly bulges from being introduced. These subsequent actions are necessary because nearly all block designs have several points where two or more seams come together.
Before discussing these more advanced techniques let’s review the two options available to quilters for pressing, the simple seams (Figure 1) on the pieces that will be combined to create more complex blocks with multi-seam intersections (Figure 2).
Option #1: Pressing All Seams Allowances Open
The advantage of this approach is that, in most cases, it produces quilt tops that lay flatter than those that are made up of pieces where the seam allowances are pressed to one side or the other. Another benefit of this approach is that when the quilt top is subsequently quilted, the open seams are typically less bulky, easing the quilting process, especially when hand-quilting. Because of this advantage, many quilters also press their seams allowances open when they construct the backings for their quilt projects.
There are only two noteworthy disadvantages of pressing seam allowances open. First, that approach generally takes more time, and, second, some quilters say it weakens the stitches by putting more stress on the stitches because the stitches are exposed.
To assure you have aligned intersections when using this method stick a pin into the open seams securing their position before you sew the pieces of the block together (Figure 3). Then press the resulting multi-intersecting seam allowance open.
Option #2: Pressing All Seam Allowances to One Side
For various reasons, some quilters prefer to press both pieces of fabric that form the seam allowance in the same direction, typically towards the darker fabric. This approach is called “pressing to the dark,” as opposed to the less common “pressing to the light.” This approach, unfortunately, produces a noticeable bulge next to the seam, which is commonly referred to as a “loft.”
If you choose that approach to seam finishing, when you later combine two pieced blocks to form a multi-seam intersection, you must align the adjoining seams so that the lofts are pressed in opposite directions. This opposite alignment will facilitate well-match matched seam intersections and will minimize the loft.
To start, you should place previously sewn blocks with the “right sides” together. At the intersection that forms, you should wiggle the fabric between your fingers until you feel them "lock" together ( Figure 4). This approach, referred to as nesting the seams, will ensure that the two blocks pull together, or nestle, once they are sewn. This minimizes the inevitable bulge and evenly disperses it on either side of the multi-seam intersection.
To accomplish this, you should insert a pin straight through the seam, like Figure 5 above. Some quilters, seeking more stability, insert a pin-straight up and down, like a "flagpole,” sticking up and out of the seam. Once this first pin is properly in place, you should then insert two additional pins, to the left and right of the "flagpole" pin (Figure 6). If, while doing so, you observe that the flagpole pin leans one way or another this indicates that the seam has shifted. In that case, you should simply remove both side pins and re-insert them, repeating this step until the “flagpole” stays straight up and down. Once you are happy with the alignment, you should remove the "flagpole” and then, finally, stitch the seam. The two side pins will keep your seam straight and aligned during your stitching, but you will need to remove them as the machine needle approaches, to avoid breaking your sewing needle. Using alignment pins takes time but the reward is well-aligned seams!
At this point, after you have pressed your seam allowance to one side you may still have some remaining loft. Fear not, though, you can use one additional technique to almost completely eliminate those unsightly bumps. That technique, which goes by a variety of names, including “twisting seams” will be the subject of our blog next week – keep an eye out for it!