During World War One embroidered silk souvenirs were very popular amongst allied soldiers to send home to their loved ones. Some were produced by hand for the most intricate designs, but many were manufactured on embroidery looms, either in large factories or by one man bands who had a loom in their house and the family came together to produce the designs. By the outbreak of World War One France was one of the pre-eminent manufacturers of embroidered silk, with the machines using punched jacquard cards to produce the embroidery in a Schiffli loom, it is estimated up to 22% of the embroidered cards made in the Great War were produced on these machines. There was obviously a set up cost involved in preparing the punched cards to produce the embroidery so the larger regiments and more general wartime designs were prioritised as commercially more sales could be expected. One popular design repeated for each year of the war was the date made up of the embroidered flags of the Allied nations, here we see 1918:

As far as I can work out, the flags depicted here are the United Kingdom, France, Belgium, Italy, Roumania, The United States of America, Montenegro, Portugal and Serbia.
In this case, the embroidery is not mounted on a card, but on a silk lady’s handkerchief:

These embroidered items were not especially cheap, an embroidered card being about three times the cost of a normal postcard and a handkerchief more than that. Despite the cost, many hundreds of thousands of pieces of embroidery were produced and sold, being ideal souvenirs to send home as they were attractive, small and light which made posting them easier for the soldier on leave in a French town. They were clearly prized by their recipients as many survive to this day and they remain as popular with collectors as they did 100 years ago.
Embroidered souvenirs like that were popular with American troops, too, although I think they were mainly from the Far East. The ones I’ve seen were pillow covers (slip covers) and jackets made of satin and embroidered with Asian themes like dragons.