Auto parts paint store - fast dry touch up paint color matched to the furniture. Whatever type of paint, masking it off well is required. No paint in holes for roll pins or detents, don't get it on the lugs or slots, and keep it out of rails.
You apply with a small brush, spraying wastes 60% of it, contaminating the environment. Top off with a layer of matte clear, to reduce the shine, and protect the color from scuffing.
If you paint the unassembled lower/upper, then add the parts, the result looks a bit more professional, and doesn't clog up the operation. One thing is important, if already anodized, leave it. Anodizing is professional grade primer - taking it off is removing the best way to get paint to stick to aluminum the industry has come up with.
