I’m no expert here, but I’ll tell you what I know. “Fustian” is a fabric blend that was used in the medieval period for everything from clothing to utility applications. Because of this range of applications, I believe it must have come in a wide range of qualities and weights.

The term “fustian” refers to a fabric with a cotton warp and a linen weft (or vice-versa, depending on who you talk to), but the idea is that the fibres are separate, not mixed together, spun together and then woven into fabric. One problem with the type of fabric carried by the Fabric Store is that it is a blend of linen and cotton fibres.

I understand that medieval fustian was most often woven in a twill pattern and brushed, so the effect is much like modern brushed denim. As a matter of fact, I have had knowledgeable people tell me that brushed denim is the closest modern equivalent of medieval fustian. That’s all well and good, but if you make something out of brushed denim, the modern context is so strong that someone may ask you if you cut up a pair of Dockers to make your doublet.....and that’s not a happy thing.

The Fabric Store linen/cotton is woven with a simple basket / tabby pattern, so it isn’t closer to medieval fustian fabric in that context, either. The cotton content is going to give it particular handling properties that are quite different than 100% linen. Cotton has a very soft, limp sort of hand, whereas linen has a bit more body. Not exactly stiff, but it isn’t like jello. A shirt made out of linen will be cooler than one of cotton because when the cotton gets wet it will cling to your body, impeding air circulation. A wet linen shirt will not cling and will encourage an evaporative cooling effect.

Less than $3 per yard for a cotton blend is fine, but if I could afford it, I’d spend the extra money and go for the 100% linen. If you’re trying to make historically accurate clothing, you’re talking about the difference of under $10 in material cost, and a gain of 10,000% in accuracy. If you’re making smallclothes, 100% linen will wear and last 20X longer than cotton or a cotton blend.

IMHO, skip the blend and go for the linen.