Soap

From Dwarf Fortress Wiki

Soap is manufactured at the alchemist's laboratory from animal tallow and lye. It appears to have no current use except as a trade item or to build constructs out of. It can become quite valuable as its value is 25 multiplied by the [MODVALUE:] of the creature whose fat it is made from. This means that soaping is a good way to get value out of megabeast fat. For example, soap made from dragon tallow is worth 1250☼. Soap does not get a quality bonus.

Constructions made from soap require the masonry labor to build.

Soap is one of many materials that results in a light gray tile or building.

Value: 25