Whiteprint

The whiteprint didn't emerge from imaging science. It emerged from ammonia fumes. By 1890, architects and engineers were drowning in blueprints—cyanotype copies with white lines on blue backgrounds. Beautiful, but the blue background made annotations difficult and caused eye strain when reading for hours.

The whiteprint process reversed the contrast: blue or black lines on white background. The chemistry used diazo compounds that decomposed under UV light, leaving unexposed areas to develop into dark lines when exposed to ammonia vapor. Easier to read, easier to annotate, easier to reproduce.

This exhibits competitive exclusion through incremental advantage. Blueprints dominated for decades because they worked. Whiteprints didn't replace them through superiority in one dimension—they accumulated small advantages (readability, annotation ease, less eye strain) until adoption tipped.

The whiteprint exhibits niche construction in technical documentation. It didn't just copy blueprints—it created a workflow where engineers could mark up originals with pens and pencils, something blue backgrounds made difficult. The white background became the standard for technical drawing precisely because it enabled iteration and collaboration.

The cascade was pragmatic: whiteprints became standard for engineering and architectural drawings through the mid-20th century. Then xerography (1959) displaced both. Digital CAD (1980s onward) made both obsolete. The whiteprint reigned for perhaps 70 years—long enough to matter, brief enough to be forgotten.

Path dependence is visible in modern document workflows. Dark lines on white backgrounds remain the standard for technical drawings. Even digital CAD software defaults to this contrast. The whiteprint's convention persisted after the technology vanished. We still design documents for white backgrounds because generations of engineers learned to work that way.

Modern document reproduction has nothing to do with diazo chemistry or ammonia development. But the expectation—technical drawings should be dark lines on white, not the reverse—traces directly to whiteprint dominance in the mid-20th century. The technology was intermediate. The convention was foundational.