Making Scrap Fabric Grocery Bags: The Frankenstein Option

(This post is a draft from the upcoming book “Sewing Cloth Grocery Bags.” A complete list of the posts can be found here.)

Frankenstein bags are what I call the grocery bags I make from mismatched fabric. Because of the way I lay out panels and gussets, I often end up with a spare panel or gusset. These go into a separate stack to be matched later with panels and gussets that look, well, acceptable together.

scrap fabric grocery bag

This bag was pieced together. The seams are covered with strap fabric. The celery is a tribute to Art Fram. (Sorta not safe to look at if the significant other’s looking over your shoulder).

I also make far more mismatched bags, when I take scrap fabric that isn’t big enough to cut a single panel or gusset and piece it together. Sometimes, I am piecing matching fabric together, and the seams don’t show. Other times, well, let’s say that these bags can be avant-garde in their appearance. They function just fine and I am using cloth that would otherwise be wasted (it is generally too heavy to be used in quilting) so Frankenstein bags cost me only my time.

The Frankenstein-model scrap fabric grocery bags are another reason why I stick strictly to cutting my panels the same size and my gussets the same length (sometimes their width varies). I can reuse leftovers as bags and those pieces do not go to waste.

Weight matters when matching panels

When matching panels to gussets, the most important criteria is weight. Are the panels and gussets of a similar thickness and hand? This is far more important than matching colors. Having one panel noticeably thinner or drapier than the other panel and gusset will result in a bag that doesn’t sew up straight. This bag will also tend to be tippy in use.

Panels and gussets can also be pieced. As you would expect, match for weight first and then for color and pattern. When you piece a panel or gusset, the location of the piecing seam matters when you sew the bag.

Panel seams work best when they run horizontally across the width of the panel, staying 5 inches below the top of the panel and at least 2 inches above the bottom of the panel. This is so the seam does not interfere with the foldover at the top and its trim line or the corner seams at the bottom. Vertical seams in the panel can work, as long as you know they won’t underlay where the bag straps go. The extra bulk can make the sewing harder. All the added thickness in a seam will make the flange sewing harder, but not impossible as long as you avoid putting a seam near the corners.

Gusset seams that are parallel to the length of the gusset are fine. Gusset seams that are horizontal to the length of the gusset are more problematic. They interfere with sewing the flanges (as do panel seams) and you must avoid putting a seam near where the gusset turns the corner.

If you piece both your gusset and your panels, then you have to be sure none of those seams intersect in the flange, as the added bulk will make the sewing machine balk and refuse to sew through all those layers. That means getting out a sturdy needle, the pliers and thimble, and hand-sewing those sections. Piece carefully to avoid the aggravation, laying the panel next to the gusset and seeing where the seams intersect before you sew the bag together.

Should your seams show?

When I piece a seam, I decide if it should show. That is, do I place the seam margins on the inside of the bag or the outside? I’ve done both. Seams on the outside get finished with contrasting narrow twill tape, which strengthens the seam and adds a design element.

I sew all piecing seams with a 5/8-inch seam, then press both seam margins to one side. If I am going to sew a layer of ½-inch twill tape over the raw edge, I trim the underlaying seam margin before sewing down the twill tape. If I am not going to use twill tape to cover the raw edge, I enclose both raw edges with an overcasting stitch. If you have a serger, use that instead. Then I press and sew down the seam margin along the edge, to force it to lay flat and reinforce the seam. On the outside of the bag, you can see the parallel lines; the ditch and the seam next to it. I do not use this seam finish if I’m putting the seam on the outside of the bag. I always use twill tape for that.

I sometimes use twill tape to cover the inside seams instead of overcasting the raw edges. It depends largely on how thick the fabric is. If the cloth is very heavy and thick, the added layer of twill tape becomes a real concern when sewing the flanges. Overcasting adds less bulk and thread is cheaper than twill tape. Both methods are equally strong. The underlaying seam margin needs to be trimmed before sewing down the twill tape. The twill tape method leaves more lines of stitching showing on the bag surface. It also adds a stiffening line, similar to a limp piece of boning.

Being willing to use up stray panels and gussets, along with piecing still more panels and gussets from odd shaped scraps, will allow you to make more bags that are essentially free. Otherwise, useless fabric gets used up and you didn’t spend any extra money, just your time. Frankenstein grocery bags may look odd, but they function just as well as your planned ones do.

(This post is a draft from the upcoming book “Sewing Cloth Grocery Bags.” A complete list of the posts can be found here.)