Now that we’ve chosen our fabric, let’s turn to the sizing of the totebag panels and gusset.
I’ve found that the most effective grocery bags have panels that are taller than they are wide. This allows for a turn down at the top edge of the bag, concealing the raw edge, providing reinforcement, and stiffening. The size I like best uses 13-by-15-inch panels; that is each panel is 13 inches wide and 15 inches tall, with a gusset 43 inches long. I provide charts to help lay out this size panel and gusset most efficiently.
You should decide on a size, either 13 by 15 inches or slightly larger, 14 by 16 inches, and stick with that size before you purchase fabric or cut anything out if you are working from your stash. This makes layout infinitely easier, your gussets will all be the same length, and your finished bags will be the same size.
Moreover, making your bags the same size ensures that any extra panels and gussets (and you will end up with a few if you make a lot of bags) can be sewed together into mismatched, but still functional bags.
The finished bags are not 13 inches by 15 inches (or 14 by 16). Some of this fabric is used up in seam margins. Some of the height is used up in the foldover that reinforces the top.
You can choose to make your grocery bags with 14-by-16-inch panels. This creates a slightly bigger bag and uses more cloth for the panels and for the gussets. It is not more difficult to cut or to sew the panels and gussets. However, you have to balance getting slightly larger bags against cutting fewer bags from your yardage and getting more waste. Keep in mind that larger bags can be more difficult to manage when an overenthusiastic bagger overloads the bigger bag. This is why I stick with 13-by-15-inch panels.
When you cut your panels, mark the top of each panel so you remember which way is up. Even though the panels are rectangles, not squares, it is easy to sew a panel to the gusset the wrong way, resulting in a very wide, very squat grocery bag that has to be ripped apart and resewn. If your fabric has a specific orientation, confirm in your mind which side is up so your fabric’s motif doesn’t end up upside down. Solid colors and tiny, overall prints don’t have this problem.
Determining the gusset width
The gusset width depends on how much fabric you have and how many panels you cut. Never cut the gussets narrower than 7 inches wide. Eight inches is better and that is how I figured most of my measurements. Nine inches is as wide as you want to go before the bag turns into a box and it doesn’t handle itself that well at the supermarket checkout. Being able to vary the width (within limits) of the gusset lets you cut the fabric more efficiently, matching the number of gussets you need with your panels.
For example, your cloth may be wide enough to allow you to cut six 9-inch wide gussets or seven 7.5-inch-wide gussets. That extra gusset may give you one more complete bag when matched up with your side panels, instead of a pair of panels tossed into the Frankenstein pile.
Since gusset width is not critical to the sewing process, sometimes you don’t even have to measure them. If you need an even number of gussets, cut the fabric to the correct length (43 inches for 13-by-15 panels), then fold the fabric in half lengthwise (that is, keeping it 43 inches in length) and cut along the fold line. Fold each piece again, cut again, and you have four pieces of fabric. Repeat this, and you have eight gussets, all the same length and about the same width. I often fold my fabric and cut along the fold line rather than mark out the widths; it’s faster and about as accurate.
You can take this one step further and do the fold-and-cut method with an odd number of gussets. Work out the approximate width of each gusset mathematically and round that number to the nearest easily marked fraction of an inch. That is, if your fabric wants to divide itself up into seven sections, each 7.8942 in width, measure 7¾-inches, cut that gusset and then divide the remaining fabric in half and cut. If you need an odd number (three instead of four), cut off another 7¾-inch width gusset, fold again and cut on the fold line giving you your gussets. Their width will vary, but as long as the length remains the same, nothing will change in the sewing or usability of the finished grocery bags. Even better, since the gusset width is close enough, nobody will ever know without taking a measuring tape to all of the bags. The bags will all look “about the same” and that’s the goal.
The gusset length
Since gussets have to be the same in length but not in width, take advantage of odd layouts, where you end up with a strip left over after cutting the bag parts. Gussets can also be pieced from long strips so long as each is three or four inches wide (or wider). The seam line will run the length of the gusset and will never interfere with sewing the flange. This seam line will not affect functionality but it will let you to use up those odd, very long scraps.
Gusset length is dependent on the size of the side panels. To find it, add the length of the right side, bottom edge, and left side of your panel. The total is the length of the gusset.
So, if you are sewing with panels 13 inches wide by 15 inches tall, add 15 (right side) plus 13 (bottom edge) plus 15 (left side) to end up with a gusset length of 43 inches. Because of the pivot points, that’s slightly longer than it needs to be. Do not try for an exact measurement to save cloth on gussets: it’s far easier to trim an inch than to add a patch. Conveniently, a 45-inch wide piece of fabric accommodates this length of gusset perfectly across the grain.
If you use 14-inch by 16-inch panels, your measurement will need to be 16 (right side) plus 14 (bottom edge) plus 16 (left side) for a gusset length of 46 inches. This extra inch means that you cannot cut gussets for 14 by 16 inch panels across the grain of 45-inch wide fabric. If you are using 45-inch wide cloth, you will either have to piece your gussets or find fabric that’s at least 46 inches long.
Any size bag will do
Keep in mind that you do not have to stick with 13 by 15 or 14 by 16 panel. If you need a much smaller bag (say 8-inch by 10-inch panels) or a much larger bag (say 18-inch by 20-inch panels) you still use the same method. As long as all your panels are the same size, and you cut your gussets to the correct length (right side length plus bottom edge plus left side length) the sewing is exactly the same. Your layout on your fabric will be considerably different from the examples provided so be sure to draw your layout on paper before making that first scissors cut.
Panels may have an additional orientation depending on whether or not your fabric has a definite up and down design. If you don’t care or your fabric is a solid color, then use the most efficient layout. If you do care, expect to use more cloth. A “with nap” layout always uses more cloth than a “without nap” layout and grocery bags are no exception. The difference may not be huge but it will be there so sketch out both orientations on paper before you cut the first panel.
Gussets wrap around the sides of the bag and bottom of the bag in a continuous strip. If your fabric has a decided up and down, then one side of the bag will have the print upright and the other side will be upside down. The only way to avoid this is to piece your gusset so the joining seam is at the middle of the gusset and thus concealed on the bottom of the bag. I do not recommend this as it is additional work and most people won’t notice anyways. More importantly, a crossways horizontal seam in your gusset will interfere with the sewing of the flange, adding unwanted bulk.
What about the selvedge?
When I lay out my panels and gussets, I always use the selvedge, unless it is buckled or pulling. The layout is far more efficient and I don’t waste expensive cloth. Depending on how wide the selvedge is, a colored line may show on a panel. Not all of the selvedge will be included in the seam margin. This does not affect functionality. However, because of how the gussets are sewn, the selvedge would have to be two inches wide to show at all; every bit of the selvedge is enclosed within the seam margin or when the flange is sewn down.
If you choose to omit the selvedges for your panels, you will need to redraw your cutting layout. Expect to use more cloth and have more waste.