There is no simple answer to the question of whether tempera or oil paint is better. Each has its own advantages and disadvantages that must be considered before deciding which is best for a particular project.
Tempera paint dries quickly, making it ideal for projects that need to be completed in a short time frame. It is also less likely to crack or yellow over time than oil paint, making it a good choice for paintings that will be on display for long periods of time. However, tempera can be difficult to work with because it can become brittle and flake off if not applied correctly. It is also not as forgiving as oil paint when it comes to mistakes, so it may not be the best choice for beginners.
Oil paint dries slowly, giving the artist more time to work with it and make corrections if necessary. It produces a smooth, consistent finish that many artists prefer. Oil paints are also available in a wider range of colors than tempera paints. However, oil paints can take months or even years to fully cure, meaning they must be stored carefully to avoid damage during this process. They can also yellow over time if exposed to too much light.