The lotion ingredients aren't important, but you should try to use one that dries cleanly. Any greasy residue may damage the bristles.
[header] How to soften a paintbrush [title] Squirt a pea-sized amount of lotion into your hand. [step] You can use any type of baby lotion. However, if you don't have baby lotion, any hand/body lotion that you have in your home will work.