Trade names in coatings — “Duco” corresponds to which type of paint? Identify the correct category for the patented/trade name “Duco”.

Introduction / Context:
Trade names are often used in practice and examinations. “Duco” historically refers to a class of fast-drying nitrocellulose lacquers widely used on automobiles, furniture, and metal products.

Given Data / Assumptions:

• Duco-type finishes are solvent-borne and quick drying.
• They rely on nitrocellulose as the primary film former.
• They are distinct from water-borne emulsions and bituminous coatings.

Concept / Approach:
Nitrocellulose lacquers form films primarily by solvent evaporation (thermoplastic mechanism). They provide glossy finishes with good buffability and were a mainstay before modern acrylics and polyurethanes became prevalent.

Step-by-Step Solution:
Associate “Duco” with historic automotive and furniture lacquer systems.Identify the chemistry: nitrocellulose-based.Select the paint category matching nitrocellulose—cellulose paints.

Verification / Alternative check:
Manufacturer literature and historical references consistently classify “Duco” as a nitrocellulose lacquer line.

Why Other Options Are Wrong:
Emulsion/plastic/bituminous/aluminium paints are different classes based on binder or pigment metal content and do not describe nitrocellulose lacquers.

Common Pitfalls:
Assuming “Duco” is a generic enamel; enamels are defined by finish and curing behavior but “Duco” denotes nitrocellulose systems specifically.

Final Answer:
Cellulose (nitrocellulose) paints