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
Zero CC tileable seed texture, edited by me to be seamless from a Pixabay image. CC0
Source Sojan Janso
Actually remixed from a pattern on Pixabay. But then noticed a very similar one on Openclipart.org uploaded by btj51q2.
Source Firkin
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
A pattern formed from a photograph of a 16th century ceramic tile.
Source Firkin
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
This was submitted in a beige color, hence the name. Now it’s a gray paper pattern.
Source Konstantin Ivanov
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Here's a bluish gray striped background pattern for use on web sites.
Source V. Hartikainen
Abstract Ellipses Background Grayscale
Source GDJ
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
Zero CC tileable pine bark texture, photographed and made by me. CC0
Source Sojan Janso
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Zero CC tileable hard cover green book, scanned and made by me. CC0
Source Sojan Janso
The image depicts polka dot seamless pattern.
Source Yamachem
Utilising a bird from s-light and some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin