When thinking about the style of custom lapel pin to purchase there are design limitations with each style. This discussion is on hard enamel custom lapel pins.
For hard enamel lapel pins there needs to be a thin line of metal separating each color. The lines keep the enamels from mixing and allow the details of the design to take shape. When the enamel colors are applied into the recessed areas the color it is overfilled. After each color is applied the enamels need to cure to harden. The curing process takes 2 – 4 hours. Colors are applied using hypodermic needles and pneumatic pressure. Todays enamels can be color matched to colors listed in the Pantone Matching System. This is a numerical reference to thousands of colors.
Once all the colors have been cured the next process is referred to “stoning”. This process is a rough polishing and smooths the over filled enamel. The purpose for the overfilling allows the final product to have a smooth surface. A finer polishing is the next process followed by plating. Standard electroplate metals includes gold, nickel (silver metal) and black nickel. Over the surface of the enamel we can screen print small details in the design that are too small to in fill. These include drop shadows, outlines, personalized names, years of service and text.
When I first started in the custom lapel pin business there were 2 options for the type of hard enamel. Synthetic hard enamel and Aoki enamels. Aoki enamels were very difficult to apply. The material was applied as wet powder. Aoki compounds are composed of glass-like material combined with metal oxides and clay into fine powder. Cloisonne powder cannot be mixed like paints or soft enamel, as each color returns to its own shade after heating. Colors are fired one at a time at 1,600F for two to four minutes to stabilize the enamel and prevent color bleeding. Each piece is fully cooled. Finishing is by rubbing the surface with a carborundum stone until all excess color has been worn away. Surface is then polished until smooth and shining. The color palate is limited to less than 300 colors. These types of enamels contained levels of lead which exceeded current CPSIA regulations for jewelry.
The base metal for these types of custom lapel pins was either copper or brass. The design was stamped into the relatively soft metal and another stamping/cutting tool was used to cut the pin to shape.Very complicated designs, designs with internal cut outs and pin on pin designs were very difficult to produce. The stamping process had to be exact so each piece in the production run fit the same. From first piece to last they all needed to be the same. As designs became more complicated the injection mold process evolved becoming a more popular choice. Present day injection mold zinc alloy eliminates the higher scrap rates and is better suited for complicated designs with multiple levels.