Do you need a "waterproof" frame for a bathroom painting?

Is there an air vent you use when your bathroom is steamy? Is your bathroom really small or average size? I have a picture directly across from my shower in a wooden frame, not waterproof, and it has never warped. I have an average size bathroom and use the vent while showering.

There’s a big difference between “waterprooof” and moisture proof. As @chyna notes, depending on the use and ventilation of the bathroom, you may not have a problem. If it were my bathroom, because I know how steamy it gets on a regular basis, then I know that I’d at least investigate the moisture proof option and see what it’d cost.

The other possibility is to give both sides a coating with an acrylic type of sealant aerosol spray.

Check with the folks at the craft store how best to apply it.

They come in a Matte finish as well as shiny but with the Matte finish, it’s really not that noticeable.

My bathroom gets pretty steamy. Its fairly large, but it does get very warm (and my mirrors all fog).

Thanks for the help you guys. I’ll probably look into moisture-proof frames.

I had a great picture (a large photograph) that I hung in my bathroom. It got moisture inside it and was ruined (stuck to the glass). If you value the picture, either don’t put it in the bathroom or look into moisture-proofing.