If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
A seamless gray background texture suitable for use on websites. To me, it has the look of stone. Feel free to modify it to meet your needs (by making it a bit lighter or darker, for example).
Source V. Hartikainen
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
Seamless pattern formed from a tile that can be extracted 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
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Remixed from a drawing in 'Очерки Русской Исторіи въ памятникахъ быта', Petr Polevoi, 1879.
Source Firkin
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Embossed lines and squares with subtle highlights.
Source Alex Parker
A nice and simple white rotated tile pattern.
Source Another One
Prismatic Abstract Geometric Background 4
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
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Prismatic Hypnotic Pattern No Background
Source GDJ
A bit of scratched up grayness. Always good.
Source Dmitry