Other forms: blueprints
A blueprint is the detailed drawing a building is built from. Study the blueprints, a blueprint for reform, work from the blueprint.
The name is literal: the old process produced white lines on a blue ground, and it was used because it copied large drawings cheaply. Nobody has made one that way for decades and the word survives for any plan. A blueprint for something is a detailed scheme.
1nounblueprintA detailed plan or drawing.
“The architect spread the blueprints for the new school across the table.”
blueprint is a plan.
Blue plus print, from a copying process introduced in 1842 that produced white lines on a blue ground.
From blue + print. Introduced by Sir John Herschel in 1842.
Etymology from Wiktionary, CC BY-SA