Cotton yarns are best for a mochila or shoulder straps, cords and matching lanyards. However, be sure to use a barrel length of 125m/50g, as this is the only way to give the mochila the right strength. The yarn should also be mercerized, because this process prevents the colors from fading and their luminosity is preserved.
I tried a lot of cotton yarns - the "Pro Lana Basic Cotton" finally convinced me. Pro Lana Basic Cotton is a very soft, cuddly, 4-thread cotton yarn that you don't want to give away once you've touched it. The glorious sheen of this yarn gives your mochilas, shoulder straps, cords or lanyards a noble touch.
In terms of quality it corresponds to the "Catania" by Schachenmayr, which is recommended in some places, but "Pro Lana Basic Cotton" is much cheaper and feels simply wonderful on the skin.
barrel length 125m/50g
Needle size 3.0 - 3.5
For crocheting a mochila, however, you must use a needle size of 2-2.5 and crochet very firmly, otherwise the bag will lack the necessary stiffness.