Sharp but soft triangles in light shades of gray.
Source Pixeden
A comeback for you: the popular Escheresque, now in black.
Source Patten
Remixed from an image on Pixabay, the original having been uploaded by darkmoon1968.
Source Firkin
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
f you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
This one is something special. I’d call it a flat pattern, too. Very well done, sir!
Source GetDiscount
As the original image 's page size is too large for its image size, I remixed it.
Source Yamachem
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
A free seamless background pattern for use on websites.
Source V. Hartikainen
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
Abstract Tiled Background Extended 12
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A repeating graphic with ancient pattern. I came up with this name/title at last minute, so you may find that there is very little of ancientness in this pattern after all.
Source V. Hartikainen
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
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
Background formed from the original with an emboss effect
Source GDJ
Traced from a drawing in 'Household Stories from the Collection of the Brothers Grimm', Wilhelm Carl Grimm , 1882.
Source Firkin
A repeating background with wood/straw like texture.
Source V. Hartikainen