What kind and brand do you use to paint in your oil paintings?

Windsor/Newton is what I like to use.
Always check out the amount of pigment in the paint you use. That’s the general measure of the quality of oil paint.

Many people spend a lot of money on series 3 and series 4 paint when series 1 or 2 will do.

If you are just getting started in painting, be proud of what you do, but don’t fall into the trap of thinking that the more money you spend, the higher quality your work will be.

If you live near a university, check their bookstore close to finals time. If they sell art supplies at the bookstore, they are usually trying to liquidate their stock at the end of the semester and you can get some great deals.

Welcome to Fluther fish4answers.

@The_Compassionate_Heretic has given very good advice here.

I just want to add that aside of pigment load in the paint you want to know the difference between pure pigments and hues.

Pure pigments are often more expensive. Hues are colors that appear in color to be the pure pigment but are in fact created substituting some ingredients.

To make it more clear:
Manufacturers of pigments use the word hue e.g. ‘Cadmium Yellow (hue)’ to indicate that the original pigmentation ingredient, sometimes toxic or expensive, has been replaced by safer (or cheaper) alternatives whilst retaining the hue of the original.

So why should you care if they look the same coming out of the tube?
As a student it is not as important but as you advance in your art the pure pigments (those without the word “Hue” on the label) are the most stable for mixing. Because Hues themselves are a mixture they often will not be as predictable or give as satisfactory a result when mixed to make other colors.

For example- I have a cobalt blue hue and a cobalt blue.
To mix both with the same amount of Cadmium yellow light produces two entirely different colors, the hue producing a grayer green than the pure pigment.

This is not to say hues are not good- they are good if you take into consideration that different brands will also yield different colors when mixed.

Most professional artists I know have several brands they use. As I look into my pochade box I have a few M. Graham (interesting company- family run with reasonable prices and nice pigment load) Utrecht, Rembrandt and Blue Ridge Oil Paint (they have hand milled historic pigments I cannot find elsewhere)

However I have used Winsor/Newton and Gamblin which are good.

This is just for your information of course. As you progress as a painter you will find the brands you prefer by trial and error.