The materials I use go through a number of criteria:
Is if biodegradable?
Is it fairly made?
Is it made with consideration for the environment?
Is it of good quality?
You won’t find me looking through cheap roll of fabric on the Saturday market on which there is no info on how it got there. I always try to find out the history of the material. I also like pure materials, so anything with plastic in it is a no go. My items and proposals will show the info on the chosen materials.
Cotton is a plant based material. It is usually soft and cool for the skin. They make perfect bases and undies for costumes, since they are easy to wash out. Cotton was not very common in historical clothing. If it was there, it was expensive. You can wash it up to 30 degrees Celsius. You can iron it after drying them flat or hanging with steam if needed.
Linen is a natural fibre made from a flax plant. It’s a bit harder then cotton, but it is stronger and goes softer after each wear and wash. It can wrinkle a lot, but that is in my eyes a charm. The making of linen costs the environment a lot less than the making of cotton. You can wash linen hand-warm (30-40 degrees Celsius) and, depending on the garment, in the washing machine. Dry hanging or flat and iron it on medium heat. Using steam is alright. During storing, new folds and creases can appear, so I can advise you to iron it again before use.
Wool is a natural fibre made from the hair of sheep, goats etc. Wool does not need to be washed a lot. Airing it is the best thing to do. If you really must wash it, do this in cold water with special soap for wool. Wash it very gently, or it might felt in a way you don’t want to. Dry it flat, after squeezing excess water out by rolling it into a clean and dry towel. Store it when it is completely dry in a cotton bag with cedar wood balls or dried lavender to keep the moths out.
Silk is the spinning thread from a moth caterpillar. It comes in various weaves and is very strong and long lasting if treated right. Wash as little as possible. If it can be washed, do so in cold water with special soap. Hand wash with a little bit of vinegar to restore the shine. Dry it flat, after squeezing excess water out by rolling it into a clean and dry towel. Don’t let it dry on wood.
Leather and fur
I do not have an issue with using leather or fur. I try to source it well. I’m a historical tailor of a period it was used a lot. I shun faux leather and fur that has plastics in them, but I do not mind using vegan items made from plants (like pineapple leather).
For different types of leather you need different care. Important is that it does not dry out. You can clean fur in the snow. Just throw it hairs down in clean snow, wait a few hours and shake it out. Another option for snow less days is to divide some baking soda on it, leave it for a few hours and shake it out and vacuum the remainders out.
For deep cleaning I suggest a good dry-cleaner. Do not ever wash it wet.
My suppliers of fabrics change more than those of yarn, so naming them would be impossible. I will always make personal colourcharts for bespoke orders, that are most up to date.
I usually buy from Historical Fabric merchants set in the Netherlands, Germany, Czech, UK, Poland and Romania. Most of these are travelling merchants as well, so there are periods of time I cannot order with them online (but I can in person). Some don’t even have online shops, so I take a batch from their stall at an event.
I have a few organic fabric suppliers (EcoTex, Pure Fabrics).
Anything else I get from larger wholesale companies and smaller fabric stores. They swap factories and consistency in fabrics so much, it makes it hard to pinpoint a location on where they were made. I can check for oekotex labels and the purity of the fabric.