A recent eBay purchase of assorted starched linen military collars in an old box of a French brand of military collars. Sizes are in centimeters, and the names are in French and English. Most of the collars are straight bands and one is a curved band. This page has scans of the collars flattened out so you can use them to make your own straight or curved WWI military collars in these styles.
These are all band collars that button into the neck of a military tunic like this one seen on General Pershing c. 1918
It just forms a small edge in the interior collar, and meets in the front without buttoning closed.
1a Mako garant. 4 fach collar M 465 Uniform 40 36:
PDF of 1a Mako garant 4 fach collar M 465 Uniform 40 36
You can use these patterns above to make replicas of this curved military collar.
1a. Qual. 4 Jacky Uniform 37:
PDF of 1a Qual 4 Jacky Uniform 37
You can use these patterns above to make replicas of this straight military collar.
ST 70 Armee 37:
You can use these patterns above to make replicas of this straight military collar.
17 Armee 45:
You can use these patterns above to make replicas of this straight military collar.