Long time lurker, first time poster. Inspired by BPL and you guys, I decided to make my own backpack and figured I would share the result. This is my first MYOG project so I didn't have to high hopes for the final product, but I think it turned pretty well considering i have never really used a sewing machine before. I finished my PCT thru in September and carried the Osprey Exos for the entire hike. The mesh back was fantastic for keeping my back from getting drenched, so I wanted to incorporate that feature into my design. The Exos is way too complicated so i looked to the Zpacks Arc Blast instead, but tweaked the design slightly and added some features. Key features that had to be included in the final design: Mesh back Highly waterresistant Shoulder strap mesh pockets Internal mesh pocket Shock cord attachment for socks/ice Axe Hands free umbrella attachment Hip belt pouches Materials: Main body - VX07 / VX21 for the bottom. Hip Belt - 210D Diamond Ripstop + 8 mm spacer mesh + 4 mm LD 29 PlastaZote foam for structure. Shoulder straps - 210D Diamond Ripstop + 4 mm spacer mesh + 10mm EVA50. 170 gsm stretch mesh for the pockets. Frame - 12 x 2 mm carbon fiber bars. Tried several different round options, before I managed to find the bars in a local RC-shop, and they work a lot better. Mesh pockets - 50 gsm mesh. It may have been a big mistake to go this light. Time will tell i guess. I'm estimating the volume to be around 40 L for the main compartment and I have no clue about the pockets. It weighs 675 g which is pretty decent for a fully featured pack i think. It has definitely been a learning experience. Lots of tinkering, trial and error and plenty of stupid mistakes; like switching the inner and outer mesh pockets around so the outer pocket is too small, and not realising it until I was done binding all the edges . Doesn't hold as much stuff as i would like, but I couldn't be bothered to redo it. This is turning into a wall of text so i better stop now and go to bed .