My games always equip the PCs with a SAP (Standard Adventuring Pack). It's contents are deliberately left unlisted, but instead it's considered to be "any mundane items a skilled adventurer would have on hand". It is automatically refilled and topped off at any settlement with goods available....and is part of the PCs living expenses.
It's been used for torches, rope, chalk, food, water, bedrolls, wedges and a hammer, paper and ink, and many many other items. Most recently some glue for a fake moustache.