Seam along week 7 - bulky seams

Previously on seam-along ...
Introduction
Week 1 - Simple edge finishes
Week 2 - French seams
Week 3 - Bound seams
Week 4 - Flat fell seams
Week 5 - Taped (stabilised) seams
Week 6 - Overlocked seams

This week I looked at how to finish seams that are very bulky. A seam can become bulky if the fabric you are using is thick or if there are many layers involved. A bulky seam can be difficult to turn and keep flat. In the example below, the seam has caused a visible ridge.



Bulky seams that intersect can quickly become very substantial and difficult to sew. The hem and intersecting seam, in the denim example below, is very thick.



To ensure that your seam sits nicely and that a big, fat seam ridge isn't visible, there are a couple of techniques you can try.

Trimming
Trimming involves removing some of the excess seam allowance. To begin, I sewed a plain seam on this medium-weight denim fabric.



I pressed the seam open ...



... then I trimmed the seam allowance back to about half the original width.



The seam sits nicely with the narrower allowance.



Commercial patterns often contain instructions about where and how to trim your seam allowance. On lighter fabrics you can cut both sides at once. For very thick fabrics you might need to trim each side separately.


Grading
Grading also involves cutting some of the seam allowance. It is used on a seam that will remain enclosed and won't be pressed open. The parts of the seam allowance are staggered, to distribute the bulk.

Once again I sewed a plain seam on some nice chunky polar fleece.



As you can see below, the seam allowance is quite thick.



After opening out the fabric and pressing the seam to one side, I cut the allowance back. The outermost side of the allowance remained the widest and the innermost the narrowest.



Conclusion
I've previously trimmed seams (following pattern instructions) but hadn't tried grading. Both techniques will be very handy. I particularly like the way the graded seam sat. Depending on the fabric, it might still be necessary to use overedging or overlocking to prevent the raw edges fraying.

Have you been seaming-along? Which is your favourite?

Next Wednesday: Stay tuned next week, when I will be investigating how to finish seams that run round curves and corners. Read more about curves and corners via Google.