A couple days ago, I made my first piece of Sarmatian garb- a Phrygian cap. While the name may be unfamiliar, you've all seen them worn by the members of a certain village of blue people.
The association was ever so lovingly pointed out by my fiancé and his best friend. I don't care if it looks silly; it amuses me and I like it. So there. :P
Phrygian caps have been around a long time and worn by many different peoples. The Phrygians in Anatolia are the namesake of the cap, but it spread to other cultures as well. The Greeks associated it with barbarism- which, in the original sense, means "not Greek" and implies an Eastern influence. Among the Romans, it became a symbol of liberty because freed slaves wore it. This association led to its use by French revolutionaries. Their caps were red and bore rosettes. It has since seen use in American and Latin American symbolism for the same reason, including on the seal of my home state.
Basically, it's a tall cap with an asymmetric, rounded apex, usually made in a material soft enough that it flops over. The apex is very blunt. The pointiest I've seen it is on a bust of Queen Dynamis of Bosporus.
According to Salisbury (2001), the cap is actually her royal headdress. The apex is pointier and curvier than most caps you can find pictured. The stars are something I haven't seen elsewhere.
It also has a trim. The trim is optional- not all caps had it. Both are options for a Sarmatian persona, as illustrated by Köhler (1871).
Köhler's Sarmatians had floppy hats as opposed to Dynamis', which stands up straight. The Dacians on Trajan's column had Phrygian caps which stood up straighter. Given that Sarmatians were raiders and some were also allied with the Dacians during the Dacian wars, it's not a stretch to assume that Sarmatians could have worn hats that stand up too. By the same token, one could also choose to have the back of the hat extend down to cover the neck like the Scythian pictured in Brezinski and Mielczarek (2002). Ear flaps are another modification that was worn, as seen in a hat from Duro-Europas in what is now Lebanon, though I haven't found a record of them among Sarmatians or their contacts. I could just be missing it, so keep it in mind. A pattern for that hat can be found here.
Whether it's floppy or stands up is probably in part due to the fabric and in part to the cut. Wider fabric up top means the hat is less able to stand on its own (since it isn't given shape by your head that high up). If your hat is thicker leather, felt, or felt-lined, it will be stiffer than if it's only made out of linen, wool, or thinner leather.
Köhler indicated that both male and female Sarmatians wore Phrygian caps. Some classical authors say they would go bare-headed (in Brezinski and Mielczarek ), so if you would feel silly wearing a Smurf hat, your outfit would still be complete without.
I had some cheap felt lying around and decided to try making my hat out of it. It's more suitable for the version that stands up. I also chose to make the kind that doesn't extend over the neck or ears. I cut it bigger than it needed to be so I'd have room to play around, then pinned it in various ways until it held the shape I wanted. Because of the shape and size of my fabric, I had to make it in two pieces (normally it would be in one piece). I stitched the edges together with blanket stitching like the Duro-Europas hat. The apex is more concave than I intended, but I'm otherwise happy with how it turned out. Now that I know what shape and size works for my head, I'll make another later on with nicer fabric and put trim on it. I'll make it taller and less concave in the front as well. I'll probably make a floppy one at some point, too.
You can use the third picture below as a base for your own. The dimensions are 11.5 x 8.5 in.
Brezinski and Mielczarek (2002), Men-at-Arms: The Sarmatians 600BC-450AD, Osprey publishing.
Harris, J, 1981, The Red Cap of Liberty: A Study of Dress Worn by French Revolutionary Partisans 1789-94, Eighteenth-Century Studies 14.3, p. 283-312.
Köhler, 1871, Die Trachten der Völker in Bild und Schnitt.
Salisbury, JE, 2001, Women in the Ancient World.