Alkyd describes a strong, synthetic resin used in paints and mediums. It serves as a binder that encapsulates the pigment and accelerates drying time. On the down side, this resin is more toxic for the environment and also is more difficult to apply due its tendency to splatter. Despite these drawbacks, alkyd is a popular choice for oil painting because it produces vivid colors, dries quickly and is less likely to yellow over time.
Oil paintings that use alkyd resin as a binder tend to have more vibrant colors than those that use other types of resins. This is because the alkyd resin helps to better distribute and suspend the pigments in the paint. This results in a more even color when the paint is applied to the canvas.