It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
This pattern comes in orange, and it looks as if it is "made of glass".
Source V. Hartikainen
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
A grayscale fabric pattern with vertical lines of stitch holes.
Source V. Hartikainen
A repeating background of thick textured paper. Actually, it turned out to look like something between a paper and fabric.
Source V. Hartikainen
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
The image depicts a seamless pattern of pine tree leaves.
Source Yamachem
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 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
Plywood Web Background background image for use in web design.
Source V. Hartikainen
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
From a drawing of the coat of arms of the Ottoman Empire on Wikimedia.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
8 by 8 pixels, and just what the title says.
Source pixilated
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
This one is something special. I’d call it a flat pattern, too. Very well done, sir!
Source GetDiscount
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