Seweing large panels of ripstop together

Any professional will tell you emphatically "yes!", most likely, but for MYOG, it really depends on what you're making. If we're talking sil, and you're making a tarp, then it can definitely affect strength and the ability to get a good pitch.

If you're making a quilt, or a stuff sack, or anything that's not going to be highly loaded, or need a ton of strength, then the answer is no, it doesn't matter.

On a shelter with a lot of complex panels that are supported? I wouldn't think it'll matter *too* much, but it's going to depend on a panel by panel basis. On an A-frame, I'd say yeah, it's going to affect the pitch a lot. Stretch is a major factor of the sag issues. Although just as big a factor could be the use of polyester thread for a ridgeline seam vs nylon. Nylon will stretch with the seam allowing a better pitch, poly wont.

Bias.

Google for tips on sewing and cutting.

> does the orientation of the threads of the fabric matter when sewing large panels of ripstop together
Absolutely!
The orientation of the threads also matters when laying out bits for (say) a tent or tarp. If you don't take this into account the result will not function in the field how you wanted.

Cheers

Since I'm not a fabric engineer, I look at lots of well engineered tents in the shops, and orient the grain of the fabric the same way on similar panels, similarly placed. It's worked quite well in getting taut canopies. More difficult, has been getting the catenary cuts right. Starting to work on a cuben tent now, and expect it to raise a whole new set of issues, due to the inelasticity of the material. This forum has been extremely helpful with all of the above.