If
the panel is rectangular - or at least one with multiple straight
sides - you can use short battens of the length of the sides. Nail
or screw them down to a board so that about one half of the panel is
contained. So if it is a rectangle, two sides will be enough. If it
is six-sided ,three pieces would do.
For
ease of assembly, a copy of the cartoon should be fastened to the
board first and then the battens fixed on top of the cartoon. The
pieces can then be placed against battens and held there with pins or
nails until the next pieces are ready.
Some
prefer to tack solder the pieces together as they foil. This can be
done in combination with the use of battens. However, leaving the
soldering iron idling while foiling and using it only occasionally is
very hard on the iron's tip and your electricity bill. I prefer to
assemble the whole and then solder all at once.
For
circular or irregular shapes a slightly different approach is
required. You can use multiple pins or nails along the perimeter to
hold the foiled pieces together. An alternative is to cut a piece of
scrap window glass to the shape of the external perimeter of the
panel. Hold it is place with nails or pins and proceed as with a
rectangular shape.