Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
A grayscale fabric pattern with vertical lines of stitch holes.
Source V. Hartikainen
Remixed from a drawing in 'Works. Popular edition', John Ruskin, 1886.
Source Firkin
Remixed from a drawing that was uploaded to Pixabay by captenpub.
Source Firkin
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
Here's a new gray "fabric" pattern. Use it as backgrounds for websites or for other purposes.
Source V. Hartikainen
Classic 45-degree pattern, light version.
Source Luke McDonald
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Your eyes can trip a bit from looking at this – use it wisely.
Source Michal Chovanec
From an image on opengameart.org shared by rubberduck.
Source Firkin
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
A dark metal plate with an embossed grid pattern and a bit of rust. Here's a dark metal plate texture for use as a tiled background on web pages.
Source V. Hartikainen
This is a grid, only it’s noisy. You know. Reminds you of those printed grids you draw on.
Source Vectorpile
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin