Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Alternative colour scheme. 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
Can never have too many knitting patterns, especially as nice as this.
Source Victoria Spahn
Here is a new seamless wood texture for using as blog or website backgrounds.
Source V. Hartikainen
Prismatic Groovy Concentric Background
Source GDJ
A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
Sometimes you just need the simplest thing.
Source Fabricio
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
This is a seamless pattern of regular hexagon which has a honeycomb structure.
Source Yamachem
Nice little grid. Would work great as a base on top of some other patterns.
Source Arno Gregorian
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A nice and simple gray stucco material. Great on its own, or as a base for a new pattern.
Source Bartosz Kaszubowski
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
Remixed from a drawing in 'An Index to Deering's Nottinghamia Vetus et Nova', Rupert Chicken, 1899. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
Retro Circles Background 7 No Black
Source GDJ
A seamless background tile of aged paper with shabby look.
Source V. Hartikainen
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper