The German Wörterbuchnetz gives you access to a number of German dictionaries, including the Grimm'sches Wörterbuch and the Middle High German Word Database (MHDBDB is the German acronym) plus a few encyclopaedias.

The Rechtswörterbuch has laws and regulations cited in there which also include medieval texts, and you can search for the names of jobs, for instance.

The Encyclopaedia of Needlework by Therèse de Dillmont was published in the late 19th century and teaches all kinds of needlework, from basic sewing stitches to lace embroidery to netting and tatting. 

A very early Italian pattern book is freely available on the net: Alessandro Paganino's book "Il Burato". The book was published in 1518 and contains lots of patterns, plus the famous picture on how to transfer patterns to the fabric. 

On-Line Digital Archive of Documents on Weaving and Related Topics - which includes articles, books and illustration not only about weaving, but about a large number of topics, down to spinning (though mostly modern spinning on machines), lace, nets, and needlework. The site had its last update back in 2016, but the articles are still available.

A Faksimile and Transcript of "Nature Unbowelled", a 17th century book with recipes for loopbraided laces.

Here is a textiles, garments, and dye glossary. It's an ongoing project for terms from the 17th century. 

The Troubadour Melodies Database does not really fit in here, but I did not want to leave it out completely. It is based on Katie Chapman's dissertation, and you can search the database with over 300 melodies from medieval manuscripts, and even compare melodies from different authors and different sources.