Today I found more information about the Lengberg Castle textile finds. Professor Beatrix Nutz just posted a slideshow-type presentation about fingerloop braids that are part of some of the finds on academia.edu. That slideshow can be downloaded here; it is written in English.
In addition to including photographs of some of the braid-containing finds and also reproductions of images showing the fingerloop braiding process, Professor Nutz's slideshow contains citations and references to fingerloop braiding instruction manuals of the 15th century, as well as some 16th and 17th century books. Some of the books contain specimens of braids pasted into their pages.
Professor Nutz's slideshow also shows the different ways that fingerloop braids became part of the textile fragments where they were found. Some of them were attached to the edges of sprang pieces that were used to ornament some of the undergarments, probably to help stabilize them. Other braids were used to ornamentally connect two pieces of linen for a garment, while still others were found as separate items and may have served as laces (fastening cords). It even includes instructions on how to work a couple of the braids found.
There is a wealth of information concisely expressed in the slideshow. It is worth studying by anyone interested in fingerloop braiding, or late medieval clothing.