dddd

I literally salvage and horde the very thin, Japanese-made tubes that I still find and take from 1980's road bikes, because they are so wide and unusually thin as compared to anything I can find at the shops. And of course no online seller discloses tube's folded widths.
These very old tubes turn up (some Specialized branded) at 29mm folded width but with a very low weight of 78g, which is unlike normal tubes today that are narrower and heavier.
A premium Turbo tube is only 67g or so, but is a narrow 22mm wide folded. They don't make a Turbo tube for wider road tires (20-25c is their printed rating).

I have used the old 29mm (actual folded width) Japanese tubes for my CX racing efforts over the past twenty-plus years in "38mm" Ritchey WCS tires that measured all of 34mm wide on my narrow Open Pro rims (I have since moved on to tubeless 42mm Rene Herse knobbies for all of my CX racing).

I find it odd that in this long-running age of progressively-wider road tires, that "standard" road tubes still haven't met the higher width/weight standards of the early 1980's.
Still waiting, even as tubeless threatens to take over (not going to happen until much slower-drying sealants get further developed).