I will collect here what I know about medieval hand sewing and how it applies to sewing Venetian clothes. Sometimes I am quoting, rewriting or adding to my class handout on hand sewing. The handout is out of date so I am not linking to it here.
The sources I have given are on the web for easy access. They are all based on books on extant material.
i. Threads and needles
In our period there were three kinds of thread used: linen, wool and silk. Seams on wool fabric could have been sewn with any thread, but silk was sewn only with silk thread. Linen could be sewn either with linen or silk.
Extant needles* are relatively thick and long, made from copper alloys, iron or bone. For ease of sewing I use many kinds of modern needles: millinery, cross stitch, darning, embroidery and beading needles. If you sew a lot, the comfort and needle suitability for the seam at hand becomes really important. The rule of the thumb is: if you can do more than one stitch at a time, use long needle; one stitch at a time – short needle.
* The extant needles I have seen range from Viking age to 16th century.
ii. Stitches
Running stitch
Is the easiest and fastest stitch. Can be used as the main seam stitch, for decorative top stitching or the first seam stitch in flat felled seams. Needle: long and thin (millinery, darning or beading needle).
Sources: Dark Age Stitch Types, Archaeological Sewing, Sewing Stitches Used in Medieval Clothing, Seam treatments on the Viborg shirt, 14th Century Sewing & Textile Information.
Gathering stitch
Is used to make a larger piece of fabric fit to a smaller one. Work two lines of running stitches close to the edge of the fabric, pull on the threads (gathering the edge) until it fits the given measurement. Needle: long and thin (millinery, darning or beading needle).
Source: Sewing Stitches Used in Medieval Clothing.
Overcast stitch aka whipstitch
Can be used as the main seam stitch, both seam stitches in flat felled seams or for overcasting the seam allowances. Needle: short and sharp for linen, dull for wool.
Sources: Dark Age Stitch Types, Archaeological Sewing, Sewing Stitches Used in Medieval Clothing, Seam treatments on the Viborg shirt, 14th Century Sewing & Textile Information.
Backstitch
Can be used as the main seam stitch in stress areas or the first seam stitch in flat felled seams for extra strength. Needle: short and sharp for linen, dull for wool.
Sources: Sewing Stitches Used in Medieval Clothing, Archaeological Sewing, 14th Century Sewing & Textile Information.
Hem stitch
Hem stitch is a variant of overcast stitch. Used to tack an edge down. Needle: short and sharp for linen, dull for wool.
Sources: Dark Age Stitch Types, Archaeological Sewing, Sewing Stitches Used in Medieval Clothing, Seam treatments on the Viborg shirt, 14th Century Sewing & Textile Information.
iii. Seams
Overcast of double-fold hems
Useful for fabric that frays like thin wool, thick silk or linen.
Right sides together, overcast the edge.
Sources: Dark Age Stitch Types, Archaeological Sewing.
iv. Hems
Double fold and hem stitch
Used on thin wool, thick silk or linen. The double fold protects the fabric edge from fraying.
Fold the fabric edge twice and use hem stitch to tack the folded edge down.
Sources: Dark Age Stitch Types, Archaeological Sewing, Seam treatments on the Viborg shirt, 14th Century Sewing & Textile Information.