Is a cuben tarp aided by being cat-cut in the same way as silnylon tarps?

Yes, the cat cuts are even more important for cuben because of the lack of stretch. For a rectangular silnylon tarp, you can pull some of the sag out of it; you can't do this with cuben.

I agree, with my cuben 10 x 6.5 rectangular flat tarp from ZPacks, I cant get a super tight pitch when setting it up in A frame. A cat cut would definitely help that though. But, that's ok because I prefer to set this tarp up in the half pyramid.

"Side question, definitive list of cat-cut cuben tarp makers would be…MLD and HMG, right? Zpacks makes good tarps but only rectangular?"

Gossamer Gear has the Q-Twin.

Yama Mountain Gear's Cirriform Tarp is worth consideration too if you prefer an A frame pitch.

I'm very happy with my Cuben Grace Solo and took it on the Wonderland this year.

Wow, I had no idea. Glad I asked. I thought cat-cut was done to negate the effect of stretching from moisture, NOT to get a taut pitch from the outset. Thanks!

Catenary curves have little to do with rain. It has to do with the physics that shape any non-rigid object when suspended over long distances. It's just as necessary for a cuben tarp if you want the tightest pitch possible.

Sticks-

I've made a few cuben tarps, both flat 9×7's and cat-cut 9x7s. The cat cut tarps will always pitch tight as a drum while flat ones only so-so. If you aren't going to use more than the A-frame pitch, go with the cat-cut cuben and don't look back.

Ryan

If I am not mistaken, ZPacks used to list cat cut as an option when buying their flat tarps. I just looked and it's not there anymore, but I feel sure it was at one time… Maybe I am wrong.

Anyway, I highly suggest ZPacks if you are looking at one, simply because they will make it to whatever size you want, just message them and they will quote you a price. There are a number of other companies (mentioned above) that also have different size tarps, but if you want something that they don't have, ZPacks can make it for you. Also, I am willing to bet that they could do a cat cut too if you want. When I bought mine, which was a custom size, I chose not to go for the cat cut though because I knew that I wasn't going to use it strictly for A Frame set ups.