Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
Zero CC tileable hard cover green book, scanned and made by me. CC0
Source Sojan Janso
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
A free tileable background colored in off-white (antique white) color.
Source V. Hartikainen
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
It’s a hole, in a pattern. On your website. Dig it!
Source Josh Green
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media