Critics called her style distinctive. They meant the bite — the way acid cut deeper in some lines, barely touched others, as if the copper itself decided what to reveal.
The bath was thirty-one years old. She'd mixed it as a student, published recipe, standard proportions. Used it to etch her first awkward plates.
Each plate dissolved trace copper into the solution. Each trace changed the chemistry. Each chemical shift changed how the bath bit the next plate.
By her tenth year, the bath no longer worked like the recipe. By her twentieth, it had developed what she called preferences — biting eagerly into certain surfaces, refusing others. Each plate trained the bath and the bath trained the next plate.
A metallurgist analyzed a sample. "This isn't an acid bath. It's a solution with a history. Every plate you've etched left something in here."
Her retrospective noted the evolution: early works clean and conventional, late works unmistakable. Critics attributed the development to artistic maturity.
The maturity belonged to the bath.
She'd thought about starting fresh. New acid, clean proportions, published recipe. She'd know immediately whether the style was hers or the solution's.
She kept the old bath. Not because she was afraid of the answer, but because the question assumed they were separable.