The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a drawing in 'Очерки Русской Исторіи въ памятникахъ быта', Petr Polevoi, 1879.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
Textured Red Brown Plastic, Free Background Pattern. Although there's already enough plastic in our lives, let's bring it to the web too.)
Source V. Hartikainen
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Alternative colour scheme for the original floral pattern.
Source Firkin
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin