More formal chap, in black, either added whalebone support for his red neck cloth or he is wearing a stock. The secret to stocks, all the high collars on the coats, and the crisp edges on the men's garments is buckram. Most commonly linen, buckram is an interface material that is stiff, flexible, waterproof and can be ironed. Buckram's secret is one of humankind's oldest trade items: plant gum.
Desert plants evolved an interesting way of defending against scrapes and cuts. Cellulose breakdown creates a sticky fluid that hardens in air. Goat's thorn, which grows abundantly in Iran, produces Gum tragacanth. Tragacanth is still used in an insane number of products, from pastels, to cake decoration, as a burn salve, and to stick cigars closed. It's harder to obtain, but unlike other gums it doesn't stick to itself. "Gum dragon" as it was called, was common in 18th and 19th century tailoring and leather work.
Brush it on thinly, both sides of the cloth and allow to dry. The result is vaguely like fiberglass, and nothing like linen with the sizing still in it. Powder is cheaper, but tedious to mix, best for small batches. Leather and cake suppliers are the best source for liquid gum dragon. One coat is pretty stiff, but two can't hurt. MOST important: the cloth shrinks when it dries. Make a big enough sheet to cut out all the parts you need.