Surface the foil-clad paper-based laminate carefully smooth out with fine emery paper to remove a layer of oxides and pollution. Degrease with acetone.
Paste Sheet of paper with the laminate trace on a foil side of the laminate. Mark on the laminate the centers of apertures, contours of breakouts and a contour of the laminate with a sharp awl. Remove the drawing. Draw printed-circuit board drawing on a foil with an acid-resistant paint (nitro enamel NC-25, asphalt paint, zapon lacquer). Here it is convenient to use a thin brush.
After the paint will dry up, drawing it is possible to retouch (to remove surpluses of paint on contours of conductors with a scalpel). If paint layer is thin, make an additional covering.
Printed-circuit board pickling: For this purpose is required the solution of iron acid in water in density=1.3 (150g iron acid in a powder to dissolve in 0.2litres of water). Pour it in a tray for photo works. Put the prepared laminate in the solution and leave it there to full pickling of not protected parts of the foil (full pickling comes to an end at temperature 20-25°С approximately in an hour). Then take out a printed-circuit board and carefully wash out in flowing water. Paint from conductors remove with acetone or carefully clean off with a knife. In places of fastening of details drill thin apertures (it is necessary to drill from a foil side) - and the printed-circuit board is ready.
Another way: for pickling it is possible to use also a solution consisting: 350g chromic anhydride, 1litre of hot water (60-70°С) and 50g table salt. Pickling is made after the solution will cool down. Duration of pickling is 20-60 minutes.
Another way: sometimes it is possible to manage in general without pickling. Non conductor parts of a foil are deleted with a sharp scalpel (or with a piece of hacksaw). It is necessary to be careful not to damage or casually not to unstuck conductor strips, especially at small width of nonconductor areas.
