… Or where to find ecclesiastical fabric… and symbols.***
I’ve been asked about this recently so I decided to write down everything I know here. Then I can send it to anyone else who is interested. With the clear understanding that I am not an expert …
Ecclesiastical Sewing sells liturgical brocade, linen, and plain fabric suitable for various kinds of vestments and other church dressing. They also sell appliqués and emblems for vestment or altar cloths, plus lace, gold braid, and actual linen. Their website is here. https://www.ecclesiasticalsewing.com/ They are very helpful and friendly. Based in Minnesota, I’d have to guess they are somewhat Lutheran, especially since they have a gorgeous brocade celebrating the Reformation. But they have a lot of Catholic flavor. For example, this June they were offering a workshop on embroidering a Sacred Heart emblem with gold thread.
This group will make vestments, but also supports DIY and has lots of expertise and material. The brocades of M. Perkins, an English manufacturer whose website is here https://www.mperkins.co.uk/ is their specialty. These brocades are often cotton/viscose though occasionally silk or polyester makes an appearance. The sudden price jump will warn the unsuspecting customer.
What’s useful about the English website is that you can compare shades of a color in order to determine exactly what you want. Check out https://www.mperkins.co.uk/green-fabrics to see what I mean. Then you can go back to Ecclesiastical Sewing, and not try to deal with customs and importing on your own.
La Lame Inc is New York based. https://lalameinc.com/ It has a HUGE selection of rayon brocades plus a HUGE selection of the various gold braids and other things that are used to decorate vestments and altar cloths and everything else. La Lame has rayon brocades at a lot of different price levels, especially as metallic thread gets involved. They also have a wide range of patterns so looking through their pages can get overwhelming. However, you do figure out what kinds of patterns are really your favorites. La Lame also has a fabric called Paschal. It is polyester, very inexpensive, and the obvious work horse of a lot of vestments. It is plain colored, where most of the rayon is decorated, but quantities of plain vestments are made of something similar. Especially I’ve seen a lot of dalmatics made of this fabric with some braid decorating them.
Gaspard Inc. is another source in the US for both vestments and fabric. Gaspard’s brocades are more limited but they have two rayon patterns that are different from both Ecclesiastical Sewing and from La Lame Inc. I made a stole with white brocade from here and it’s lovely. https://www.gaspardinc.com/vestments.html
There are two other big sources of fabric for vestments that I’m aware of, regular fabric stores and Etsy.
Joann Fabric, Vogue fabric online, and some others all have a variation on the fabric in the header image. The circle with a cross inside it comes in two sizes, one about 4 inches across and one about 6 inches across, and lots of colors. Just pay attention when looking.
https://www.joann.com/brocade-fabric-gold-cross/15735046.html
https://www.voguefabricsstore.com/metallic-church-brocade-red-gold.html

This is really the same pattern as the image header but the pattern is about four inches across. The green pattern in the header repeats in about 7 inches.
Etsy is a huge source of liturgical brocade. I saw fabric there from both Ukraine and Greece, plus random other places. La Lame is clearly getting a lot of their fabric from Greece because the Etsy sellers from Greece have a lot of the same patterns. Parmatex is one of the big names for this. Places on Etsy also cater to the Orthodox community so the fabric selection has yellow, blue, and gray which we, by and large don’t use. Too bad about the blue; it can be luscious.
With respect to the Orthodox question, I found several places online selling fabric for Orthodox vestments. Here’s one with slightly different fabrics. https://www.oramaworld.com/en/c/9000_9600_9630/Sip_Fabrics . Tons of Etsy sellers address the Orthodox fabric question.
*** A last comment on the vestment question. Embroidered symbols are a lovely addition to vestments. They can be bought and applied separately, but they can also be embroidered directly on to a vestment or some part of it. All the sources listed above will sell appliques. However, another option is to do the embroidery with an embroidery machine. Ecclesiastical Sewing sells patterns. So does Windstar Embroidery https://www.windstarembroidery.com/ and Windstar has an enormous collection of beautiful and ancient liturgical patterns. The really interesting part of this is, that libraries in Loudoun County have embroidery machines that can be used by anyone, in their MakerSpaces. I don’t know about Fairfax Libraries or others in the area. A design downloaded from Windstar can be taken to the library on a USB and voila!

Design from Windstar, embroidered at the Loudoun County Library, three inches across