I have wallboard in my bathroom I would like to paint it . what do use

There are paints formulated for bathrooms that have protective ingredients in them for moisture

It's in the prep. Use a liquid deglosser purchased from hardware dept. Some call it liquid sandpaper. Prime with Kilz and paint with whatever.

First, scrub a small area with a solution of household detergent and warm water. Rinse well and towel dry. Then soak a cotton ball, Q-tip or soft rag in alcohol and rub it back and forth over the cleaned area.

If paint comes off, it's latex and another coat of the same is in order. If the paint doesn't come off, it's oil-based, and an oil-based primer is a must.

Then you have options for the finish coat, and different types of latex or oil-based paint can be used.

At this point, after testing and priming (if needed), you might want to discuss both your options and paint performance characteristics with the paint experts at your local hardware, or paint store.

It's best to remove the wallpaper. Take 1/2 cup of snuggle in a quart of warm water, then spray your walls. Wait 15 minutes of so and spray again. the paper will come right off. Your paint job will look smoother.

Good luck.

I agree- you'll get the best results if you remove the wallpaper first. Its time consuming but not too hard to do. If you have, use a steamer and if not, you can usually rent one without too much difficulty.