You've found a beautiful old picture frame at the local flea market, but it's in pretty bad shape. You love the look of gold leaf and would love to apply a gilt finish to the frame. The process of gilding involves layering on a coating of sizing and gesso with a final layer of gilt on the top.
Clean the frame thoroughly with a sponge that has been dipped in warm soapy water and squeezed out. Sand the frame lightly with fine grit sandpaper. If the picture frame is heavily coated with old paint or varnish you'll have to strip the wood with a commercial paint stripper before you proceed with the sanding.
Dilute the acrylic paint with a matt medium in equal parts. This will help the gesso layer adhere better. After you've adequately prepared the surface of the picture frame, apply the acrylic paint over the entire picture frame in even strokes.
Paint the gesso, a mixture of size and chalk, evenly over the picture frame. The gesso will become tacky as it dries. The gilt leafing will be applied when the gesso has reached the tacky stage. Test the gesso to be sure that it is ready by lightly pressing your knuckle into the gesso.
Place the gilt leaf tissue paper over the picture frame and brush gently with a very soft brush to transfer the gilt leaf onto the picture frame. Overlapping slightly, continue transferring the gilt leaf tissue paper onto the frame until it is covered to your satisfaction. Gently buff the frame with a soft cloth.
It's a good idea to apply the gilt leafing to the crevices first by using a small piece of the gilt-covered tissue and a small brush to transfer the leaf into the crevices. Wear cotton gloves or rub talcum powder onto your hands when handling the gilt to prevent it from tarnishing.