I painted my cabinets before I assembled them. But if you are painting existing cabinets, you will want to remove all of the doors from the base cabinets.
To prep all of the cabinets for painting, sand all of the surfaces with a very fine grit sandpaper. This helps rough up the surface of the cabinets so that the paint will adhere better. I would recommend a 220 grit sandpaper or higher.
Next, you will need to prime all of the surfaces. The primer that you need to use is the Zinsser B.I.N. Primer, which is a shellac based primer.
The next step is to start painting. Paint sprayers create a nice, even finish. That way I could avoid any brush strokes from paint brushes and rollers.
To get the best results with a paint sprayer, you need to keep it moving at a constant speed. You want to lightly cover the surface and avoid paint build-up.
To paint the IKEA base cabinets, use a foam roller and a paintbrush. Apply the paint evenly to all surfaces in thin layers.
I used this HANDy Pro Pail and it was so helpful! I needed to use both a paintbrush and a foam roller to paint these cabinets. And the HANDy Pro Pail has a spot for both of those tools while still being portable.
I recommend waiting at least 24 hours after you paint before handling the cabinets. Letting the paint cure completely is critical if you want the finish the last long term.
Put the cabinet pieces back together. After you assemble your cabinets, you can also add the hardware.