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Amphibionics
dpi, then make two transparencies and lay them on top of
each other. Make sure that the traces line up perfectly, and
then staple them together. A glass weight should then be
used to cover the artwork, ensuring that no light will pass
under the traces (approximately 3-mm glass thickness or
greater works best). Use a 10-minute exposure time at a dis-
tance of 5 inches.
3. Developing your board—The development process removes
any photoresist that was exposed through the film positive to
ultraviolet light. Warning: The developer contains sodium
hydroxide and is highly corrosive. Wear rubber gloves and
eye protection while using it. Avoid contact with eyes and
skin. Flush thoroughly with water for 15 minutes if it is
splashed in eyes or on the skin.

Directions: Using rubber gloves and eye protection, dilute one
part M.G. cat. #418 developer with 10 parts tepid water
(weaker is better than stronger). In a plastic tray, immerse the
board, copper side up, into the developer, and you will quick-
ly see an image appear while you are lightly brushing the
resist with a foam brush. This should be completed within
one to two minutes. Immediately neutralize the development
action by rinsing the board with water. The exposed resist
must be removed from the board as soon as possible. When
you are done with the developing stage, the only resist
remaining will be covering what you want your circuit to be.
The rest should be completely removed.

4. Etching your board—For best results, use the 416-E
Professional Etching Process Kit or 416-ES Economy Etching
Kit. The most popular etching matter is ferric chloride, M.G.
cat. #415, an aqueous solution that dissolves most metals.
Warning: This solution is normally heated up during use,
generating unpleasant and caustic vapors; adequate venti-

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