Of the five pokemon in Japan which can learn String Shot, only Caterpie produce actual string. Weedle produce a weak fiber similar to cotton and of use solely for the construction of textiles. Wurmple produce a smooth silky thread which is pleasant to the touch, while Spinarak and Ariados produce a powerful adhesive.

For utility, however, none of these are as valuable as Caterpie string. For string can be used in archery, to make ropes, or for a thousand other things, half of them improvised in time of few other materials. Other fibers made from plants are occasionally used elsewhere, typically in places which lack trade links with Viridian City and its adjoining forest where most of Viridian's people work. The task is tough and thankless, for it requires extensive harvesting of leaves to feed the bug pokemon year-round. The string after spraying must be collected by hand, they must avoid battling them (save for the few lucky enough to afford everstones) as evolution weakens the string, and profits have never been very high.

It was from this forest that a young Caterpie farmer named Giovanni turned to gambling to supplement his income. It is said that he so hated the work that at the height of his power, Caterpie was the only local species of pokemon which he declined to obtain for his collection.