Cutting Large Pieces of Fabric

When I first started making tents (40 years ago) I cut patterns out of cardboard about the weight of a cereal box. I would then cut the fabric out with a hot wood burner with the fabric lying on a big aluminum sheet.

Now I just draw on the fabric and cut it out with a scissors or rolling cutter. I'll probably not make the same thing twice so it isn't worth the extra effort to make a pattern. I hem all the edges so the toxic burning of the fabric isn't worth it either.

I'm also less concerned with quality because I'm just making the stuff for myself. If it works I'm satisfied even if it doesn't look too good. Forty years ago I started out making a few tents for other people so I was more concerned about looks.

Things that people use for sheetrock and plywood that you already have on hand can be used. chalk lines, squares, etc.

For straight line cuts, I do layout on the fabric, then cut.

For curves I make a template, transfer to the fabric, and then cut.

I find that with the lightweight fabrics it is too easy to get things pulled out of shape while making the numerous measurements and marks required for large shallow curves, hence a ridged template.

I did not have a large cutting surface/table, so I got a very large empty cardboard box and opened it up. When laid out on my living room carpet, I can use a rotary cutter or scissors. For smaller pieces, I use a self-healing cutting mat.

I found silnylon to be tricky to work with. It is thin and slippery, and that shows up in cutting if you aren't careful. I suggest using lots of pins and tape.

A friend of mine in the commercial clothing design business says to use a number of bacon presses to hold the fabric down on the cutting surface. A bacon press is a heavy cast iron weight for pressing bacon while it cooks. Apparently a number of those will keep the fabric from sliding around too much during the cut.

–B.G.–

I use unopened food cans to weight fabric

Have had good luck with Ping-Pong tables bought cheap from places like Walmart for around $100. They generally fold up, and have wheels so the folded table can be moved against the wall, or moved while you are cutting to get to different sides of the table. The only problem is that they are made of a composite material that will sag after a time, especially in a moist environment, like a basement. But slight sagging doesn't seem to be a problem. The tables are 5' wide by 9' long, just right to unroll most silnylon. As already noted, tacks and weights are needed to stabilize the material for marking and cutting. The composite does take tacks well, though.

Like Daryl, I use a marker, usually a yellow china pencil, and scissors, both kept very sharp for accuracy and ease of cutting. The Fiskar scissors slice easily through the fabric when sharp, so the Fiskar scissor sharpener is a must accessory. The biggest problem is finding places to put all the stuff on the table when it needs to be cleaned off to start a project.

What also works well is marking the line where the material will be sewn, and then allowing the desired seam allowance when cutting. So the line is used for sewing, not cutting, but you can make two lines if you want. It's a little tricky when doing lap felled seams, but just requires some thinking before cutting (Think twice, cut once – hah-hah). Unlike some, I always use small pins to position the fabric pieces together before sewing, but make sure the pin holes are only between the stitch lines in the seam where there are several layers of material over which sealer will be applied. The material is held taut but not stretched at both ends while sewing, and each pin is pulled out before the material goes under the needle. All that, because silnylon has a way of constantly changing its dimensions, especially while being sewn together.

Have also tried creasing the fabric along the stitch line with an iron before sewing, being careful to touch only the crease with the edge of the iron so that the material outside the seam will not be damaged. Takes some time, but greatly simplifies doing a lap felled seam with a home machine.

Now some like Judy Gross will probably have something to say about this, but it should be kept in mind that she is a master seamster. For the rest of us, necessary precautions take some extra time initially, but save tons of time in the long run.

Thank you, some helpful comments. My apartment is small, but I have a garage, so I will probably try to find a large piece of cardboard I can use to keep the fabric stretched and clean. Maybe I will also use cardboard to trace the catenary curves. Time to buy a long straight edge!

As for sewing silnylon or other light fabrics, I have been using a combination of mini binder clips and hand stitches at key points. I haven't tried ironing the fabric, but maybe that would be a good idea for the long flat felled seams.

Another vote for the chalk line. But I recommend putting barely any chalk in at all, otherwise it will make a mess. Put chalk in, pull the line out and retract it, then pour all of the chalk out and snap a couple lines on concrete. Then move on to silnylon. After I did that I still had enough chalk in the thing to do an entire supermid clone. I snapped the lines and then used a spreadsheet and framing square to mark points for the catenary curves.