Adhesive is almost never found in its pure form in the world. As such, when one is attempting to search for adhesive, it is advised to search for the items which break down to adhesive such as duct tape and glue instead of the raw material. However, anglers drop large amounts of adhesive when killed.
The base price for a shipment (25) is 1,000 caps, equating to 40 caps per adhesive. For comparison, duct tape (1 adhesive) is 12 caps, and wonderglue (2) is 20 caps, making it four times as expensive simply for convenience. One such way (see below) is to craft vegetable starch within the settlements by farming all of its requirements and crafting it personally at a cooking station.
Adhesives are efficient in terms of yield per weight, with even the least efficient adhesives providing upwards of seven adhesive per pound of weight.
While not strictly a rare item, adhesive tends to be one of the most sought after and short supplied resources in the game, due to being used for almost all weapon and armor modifications.
Vegetable starch is a source of adhesive and can be created at any cooking station using three corn (6 caps each), three mutfruit (8 caps each), three tato (7 caps each) and one bottle of purified water (20 caps each). Scrapping the starch yields 5 adhesive at a cost of 83 caps, 16.6 caps per adhesive. Creating vegetable starch also provides a large amount of experience, making leveling very possible with only creating the substance. All of these ingredients can be readily available at settlements, with farming and a water purifier.