Hard Enamel vs. Soft Enamel - What You Should Know
Whether you're looking to create your very own hard or soft enamel pin or are simply curious about the differences, you're in the right place!
In the realm of enamel pins there exist two main types: hard enamel and soft enamel. Each has their own set of benefits and drawbacks and the finished products have very distinct looks.
What Is Enamel?
First let's talk about what enamel is and how it brings your pin designs to life.
We all know our teeth are coated in enamel to protect the inner layers from damage but vitreous (or glass-like) enamel, used in jewelry and pin making, is completely different.
The enamels used in pin making are made from a powdered and colored glass, the consistency of baby powder, that's typically been mixed into a liquid solution. This liquid solution can come in almost any color you can imagine and will end up hardening and creating our pin's colored surfaces.
Enamel must be fired in an oven in order to harden properly, though the process involved differs somewhat between hard and soft enamel pins.
What Are The Differences?
While I highly suggest you read further about the differences in the processes, to understand all available options, here's a quick at-a-glance look at the differences between the two types:
- Smooth reflective finish.
- High polish.
- More durable.
- Colors are more vibrant.
- More expensive.
- Less metal plating/coloring options.
- Recessed textured finish.
- Low polish.
- Less expensive.
- More metal plating/coloring options.
- Less durable.
- Colors are less vibrant.
- Scratches more easily.
Here's a great example of the visual differences between a hard and soft enamel pin.
Hard enamel pins have a glossy, reflective and highly polished finish in which the debossed areas filled with enamel colors are flush with the surrounding metal, enhancing the vibrancy.
Soft enamel pins have a textured and debossed finish in which the debossed areas filled with enamel colors are recessed from the surrounding metal, enhancing the texture.
Hard enamel pins are fired at a higher temperature which maximizes the hardness of the vitreous enamel, making them more durable and scratch resistant.
Soft enamel pins are fired at a lower temperature which forgoes maximizing their hardness, making them somewhat less durable and more prone to scratching.
You may be wondering why soft enamel pins aren't simply fired at the same temperature as hard enamel pins. Wouldn't they achieve the same hardness and durablility?
The answer is that yes, they would, but they would also lose a lot of their color. The higher temperature you use to fire the enamel color the more translucent and glass-like the enamel becomes. This isn't a problem from hard enamel pins which are filled to the maximum and have very thick enamel layers. However, since soft enamel pins are only partly filled you need to retain as much of the opacity of the colors as possible. Hence, the soft enamel pins are fired at lower temperatures.
Hard enamel pins require multiple firings to harden the enamels, one firing the application of each color. For example, a pin with eight colors would need to be fired eight times. This increases the work involved which increases the cost.
Soft enamel pins required only one firing to harden the enamels, after all of the colors have been applied. For example, a pin with eight colors would only need to fired once. This minimizes the work involved which decreases the cost.
Metal Plating/Coloring Options
Hard enamel pins can typically only have their base metal electroplated, not painted. This is due to the hard enamel requiring grinding after firing, which would chew away any paint applied beforehand. This means you're typically limited to metallic finishes which can be electroplated after grinding.
Soft enamel pins can have their base metal electroplated or painted any color you wish. This is due to the lack of grinding the soft enamel requires. This means the electroplating or paint applied to the pin before firing will stay on.
You may be wondering why custom metal paint colors can't be applied to hard enamel pins after grinding them.
The answer has to do with the fact that hard enamel pins require grinding and soft enamel pins do not. If the manufacturer were to apply the same metal paint to a hard enamel pin before coloring and firing it would come out of the kiln perfectly fine, just like the soft enamel. However, that same pin still has to undergo grinding to level the hard enamel down to be flush with the metal. This grinding would eat away the applied paint and ruin the finish.
The reason the paint can't be applied after grinding is complete but electroplating can is that electroplating is an automatic plating process and doesn't require any dexterous application of color. Hand painting a custom metal color onto a finished pin while trying to avoid getting paint on the enamel would be a nightmare. Manufacturers just can't do that.
What's The Process?
It's important to understand the process that goes into making each type of enamel pin to understand what design options are available to you. We won't discuss the entire pin making process from start to finish, but rather cover the coloring process.
Once your enamel pin has been stamped out from the die cutting machine it'll have debossed (pressed in) areas that will accept the enamel coloring. The sides of metal surrounding these areas will keep the enamel colors from touching each other and mixing together.
The manufacturer will follow the designs you'd given them and begin preparing the pin for coloring and other design features. This is where the process diverges between hard and soft enamels.
Here's a photo of enamel coloring being applied to some pins of a soft enamel style.
Hard Enamel Process
If you'd selected hard enamel for your pin the very next step will be to color and bake each of the colored sections one-by-one (think paint by numbers!). The manufacturer will use squirt bottles with tiny nozzles to inject each separate color into their areas, one color at a time. In this hard enamel process the debossed areas are filled to the brim or even overfilled slightly to ensure maximum fill.
The pins must be baked between each application of color to prevent multiple colors from overflowing and running together, since they're so heavily filled.
(i.e. All areas that need light-blue coloring area filled at once, then fired. Then, all areas that need red-orange coloring are filled at once, then fired again.)
It takes a lot longer to fire the pins multiple times versus just one firing for soft enamel, so the cost is increased slightly.
Once each color has been fired and hardened individually the pins are polished against a grinding wheel to remove excess or overfilled enamel. This grinding levels the enamel to the same height as the base metal, giving the pin a smooth and flush look.
It's at this stage that electroplating can be applied, if requested. However, options are often limited versus soft enamel designs since this electroplating process is occurring after the coloring and firing process. Typically, you're limited to metallic finishes that can be easily electroplated and will not be able to select custom painted metal colors in this hard enamel style.
Regardless of any plating processes, polishing commences using a cloth buffing wheel to buff out any marks left by the grinding. This ensures a silky and shiny glasslike surface across the entire pin.
Then, it's finished!
Soft Enamel Process
Unlike hard enamel pins, soft enamel pins don't go directly to be colored after being metal stamped and punches out. If you'd selected any special coloring for the actual exposed metal of the pin, that coloring is applied now.
There are lots of color customization options available versus the hard enamel alternative due to the lack of grinding required after the colors are baked.
Just like the hard enamel pins, colors are then applied one by one into the debossed areas of the design. The difference here is that the pins do not have to fired in between each color. The enamel is only applied in a thin layer rather than being filled to the brim or overfilled. This keeps the colors safely in place while working and eliminates the need for firing in between each color.
After being fired, the pins skip the grinding phase, which keeps any custom metal paint colors in place.
Then, it's done!
Which Should I Choose?
While you may already have an idea of which style you prefer for your own design in mind, let me share my own experiences with you to help you make the most informed decision!
Though each of the hard and soft enamel styles have their pros and cons, aside from their distinct visual differences, some of these attributes may not be as prevalent as you think.
The cost will obviously vary by manufacturer but the cost difference between the two may be negligible. It may only cost a few cents more per pin to have it done in a hard enamel. Be sure to check with your manufacturer about the difference if you're on the fence!
The durability distinction is something I find either makes a noticeable difference or not much at all, depending on the design of the artwork. Soft enamel can be soft enough to dent with your fingernail if you press with enough force. Why you'd be pressing your fingernail into the color I don't know, but it gives an idea of how much it can withstand. The issue comes into play when you have a design with a large open area of color that may be susceptible to object coming into direct contact with it and pressing in on it. However, if your design has lots of smaller more detailed areas there shouldn't be room enough for anything to get in and press on the colors.
That being said, the durability aspect should come into play based on your design. It may not be any issue at all for your art.
I Hope This Helped!
Thanks so much for reading my article and I hope this helped you make a more informed decision on which enamel was right for your pin design.
If you have any questions you'd like answered you can send me a message on Facebook and I'll try my best to help. Also, let me know in the comments if you're interested in any other informational articles regarding pins and pin making. Feel free to share a link to show off your pins in the comments below as well!