I played around with a bunch of versions, these are the latest that work for the required parameters (1 liter nalgene, 1 liter regular plastic bottle, 24 oz bike bottle, 18 oz bottle), had to go to dual straps to avoid excessive sway, and for times when a small bottle is used in a full liter sized water bottle holder, I added a small internal frame to the holder, weight of these is 10 grams for the size that fits 18-24 oz best, and about 12 grams for the size that fits 1 liter nalgene, 1 liter disposable, and down to 18 oz. Material is 2.2 oz 70 denier coated nylon. I don't think I'd use silnylon on these because of the constant sway pressure on the bottle holder when walking.
These are dual use, either pants belt or hipbelt. Main concern is that zpacks cord is a bit too narrow and might eat the hipbelt edges over time. I also made these in a cool 4oz blue mesh I found at the fleamarket, but the orange is lighter and stiffer overall.
I call these h4o because it's the forth major version, and the first one that actually worked well for all bottle sizes.
the quest for the perfect water bottle holder continues, but these are pretty solid, a few dimensions are off but otherwise work fine.
Materials 2.2 oz coated nylon, 1.5mm zpacks cord, tiny zpack cord locks, and 1/2 inch grosgrain. Plus a small rectangle from a flat sided plastic bottle, like milk or juice.
Uncoated 1.9 oz nylon would take them under 10grams each. Silnylon would take them further down, closer to 7 grams, but I suspect durability would be an issue at that point.
Personally, I want less, not more weight, on my shoulder straps. I did make shoulder strap pouches though, those turned out nice, for little stuff.