It's a common misconception that "soft" enamel is less sturdy than hard. The soft and hard terms have to do with how the pin is created, and the end result for both is a beautiful, hearty pin.
Because they undergo less heat, soft enamel pins can have dyed metal, whereas hard enamel is limited to gold, silver, and nickel (with only gold being fool-proof.) For this collection, we wanted more color options when we were designing them, and decided we didn't want to split the collection between hard and soft.
For the customer, the biggest difference you'll notice is the texture. Soft enamel pins are slightly recessed, giving them a very cool texture. Each pin was designed with this texture in mind, to take the most advantage of it.
We're super excited about it. Our last kickstarter included a free soft enamel (the Home pin) and our manufacturer does them amazingly! We're really excited to dip our toes further into this style of pin.