At some point in the past it crossed my mind to make templates for different sizes of box bottom corners so I could quickly outline the corners without having to measure them out each time. I never got around to it because I wasn't sure having a bunch of different corner outlines to keep track of would be any more efficient than measuring them out each time.
But I came back to the idea after seeing a square sewing gauge tool that included a number of different measurements. It looked really useful, and at some point the idea of the square gauge merged with the box bottom corner idea and became these box bottom corner gauges.
I've been using these gauges for the last couple weeks to test them out and found a few more uses for them. Here's what I've come up with so far:
If you want to make the box bottom smaller or larger, these can be used to draw your new size corners. In the photos above the tiny zipper pouch is Size 1 from the Intro to Improv Zip Pouches, but without dividing the fabric into sections and using a 1.25" corner outline rather than the 0.75" included in the pattern. Here's another pouch where I used the 1" square to outline the box bottom corners.
One thing to keep in mind is in most cases you don't want the box bottom corners to intersect with any piecing seams (i.e. seams that aren't a bottom or side seam). So for the tiny pouch above, I knew it would be so small that dividing the fabric into sections would mean the corners would intersect with the division seams, and it would look weird on the finished pouch and probably be a pain to sew. So in this instance I skipped dividing the fabric, but in general, just keep in mind you don't want the box bottom corner to intersect any piecing seams.
I like using the cut out way to make these corners as opposed to where you don't cut out the box bottom outlines and make a wedge with the bottom corner and then sew across it to create the box bottom. The one thing I've noticed about using the cut out method is sewing the corners comes towards the end of the construction process, and the fabric pieces can get slightly off kilter as you sew.
If I don't go back and trim the corners square before sewing them, they can end up pretty wonky. They'll be angled one direction or another, or all the corners will no longer be the same size. So I've learned to clean up my corners, and these gauges are making it quick and easy to square them up.
When I want to add magnetic snaps to a project, and I'm using a 3/8" SA or smaller, 1.25" is my magic measurement for where to center the snap washer. That leaves room for the seam allowance, as well as enough space to topstitch without the snap getting in the way of the presser foot.
Spacing Quilting Lines
For some things I'll use a few quilting lines to hold together layers of fabric/muslin/fleece and these gauges have turned out to be pretty handy for spacing the lines out evenly. Usually I use this quilting on the lining, so it doesn't need to be perfect, but I still like the lines to be somewhat evenly spaced. The squares on the gauge also have a nice t-square effect that helps keep things straight.