Those new to the mechanical keyboard community tend to underestimate the importance of keycap profiles when ordering keysets. With so many unusual (but cool) layouts, it can be costly to get all the necessary keys to cover your board. However, there are some non-sculpted profiles that make it a breeze. DSA is by far the most popular of these, and several of the most popular custom sets in the community have been produced in this profile.
Similar to the SA profile, DSA is actually an acronym that tells you about the keycaps. It stands for DIN, Spherical, All Rows. So, let's break that down. "DIN" refers to the DIN ergonomic standard, which was developed in West Germany in the early 1980s. It dictated lower profile switches and keycaps than what were widely available at the time. "Spherical" means the curvature of the tops is rounded rather than straight like an OEM or Cherry profile set. And the "All Rows" bit means all the rows are the same shape. That's why DSA is so popular in the custom scene.
Because non-standard keyboard layouts move keys around, you often need to buy multiple specialized kits to cover them. You need to take into account both key size and the row each key is on, but DSA takes away half of that complication. Since all the rows are the same, all you need to do is make sure you have keys that are the right size for your board. That saves money on manufacturing and helps make more keyboards compatible.
It can take some time to get used to typing on DSA. Your fingers will land at odd angles at first because of the lack of sculpting. It's best to have a board that tilts up a few degrees at the top to make up for the completely flat profile. However, the low-profile design makes DSA caps great for travel keyboards.
Signature Plastics in the US makes the "official" DSA keycap sets, but plenty of other manufacturers have created their own versions of the DSA molds. Signature Plastics makes DSA keycaps in both ABS and PBT plastic. You can see the two versions compared above. PBT plastic is harder and has a neat "grippy" texture. The legends on these caps are dye-sublimated—dye is integrated into the plastic so it won't wear off. ABS is a softer plastic, but the legends are double-shot. That means the legend is a separate piece of plastic, allowing for more color combinations.
The gray/blue set I used above is a PBT set called DSA Quartz. Some other popular DSA sets include Granite (PBT), Lightcycle (ABS) and Overcast (ABS). As with other keycap sets, most DSA sets are only available via group buys. However, some are remarkably accessible—you can just buy a few of these sets direct from Signature Plastics or KBDfans without waiting through a group buy.
We'll cover interesting DSA keycap sets that launch down the line.