Baekeland set phenol and formaldehyde under heat and pressure to get Bakelite.

By the early 1900s products like shellac, ivory, and natural resins were expensive and inconsistent. Chemists had combined phenol and formaldehyde before, but the result was a soft, sticky resin that softened again under heat, so it was useless as a solid.

Leo Hendrik Baekeland, a Belgian-born chemist already rich from his Velox photographic paper, set out to tame the reaction. On July 13, 1907, he filed his heat-and-pressure patent, in which he carried the condensation to completion under pressure.

The difference was in the finish. Instead of a resin that melted when warm, the new material was a hard, nonconducting, machinable solid that could be molded into shape once and never softened again. He called it Bakelite, after himself.

Bakelite was the first plastic made entirely from synthetic components, and it made Baekeland's fortune; he founded the General Bakelite Company in 1910. It was prized for electrical insulation and from radios and switchboards to jewelry and billiard balls.

Heat and pressure make a melty resin unmeltable

Taking the reaction to completion under heat and pressure made a cross-linked solid

An unmelting, nonconducting material was exactly what electrical products needed

Being moldable made it manufacturable, not just an interesting resin

Controlling the finishing step turned a failed predecessor into a product

If the reaction keeps melting, drive it further under pressure until it sets for good; the finishing step, not the recipe, turns a curiosity into a product.

Bakelite created the modern plastics industry and the word itself became a byword for molded plastic. It was eventually displaced by newer thermoplastics, but its model of a cheap, moldable, nonconductive material shaped the age of plastics that followed.