In paints, _______ is an oil to which the base is mixed.
Try it first: pick an option, then read the explanation.
The Composition of Paint
Paint is a composite material made of several key ingredients. The solid components, like the base (for body) and pigments (for color), need to be suspended in a liquid so they can be applied. This liquid component is fundamental to the paint's function, acting as the carrier for the solids and forming the final film.
Detailed Analysis of the Options
(a) plasticiser
Role: A plasticiser is an additive, not a main component. It is added in small quantities to certain paints to increase the flexibility of the dried paint film and prevent it from becoming brittle and cracking. It does not act as the main liquid carrier for the base.
(b) solvent
Role: A solvent (or thinner) is a volatile liquid used to dissolve the binder and reduce the paint's viscosity, making it easier to apply. While the vehicle contains a solvent, the term "solvent" alone refers only to the evaporating part. The oil itself, which stays behind to form the film, is the non-volatile part of the vehicle.
(c) vehicle
Role: This is the correct answer. The vehicle is the entire liquid portion of the paint. It is the "oily substance" that the question refers to. The vehicle's job is to carry the solid particles (base and pigments) in a suspension, allowing them to be spread evenly on a surface. It is also called the binder because its non-volatile part (the oil itself) hardens to form a solid film, binding everything together. Classic examples are linseed oil, tung oil, and poppy oil.
(d) pigment
Role: A pigment is a solid, finely ground powder that provides color to the paint. It is one of the components that is *mixed into* the vehicle; it is not the vehicle itself.
Paint Components: Solids vs. Liquids
| Component | Role | State | Example |
|---|---|---|---|
| Vehicle / Binder | Liquid carrier; forms the final film | Liquid | Linseed Oil, Tung Oil |
| Base | Main solid; provides opacity | Solid | White Lead, Zinc Oxide |
| Pigment | Provides color | Solid | Lamp Black, Iron Oxide |
| Solvent / Thinner | Reduces viscosity | Liquid (Volatile) | Turpentine, Water |