From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Background pattern originally a PNG drawn in Paint.net
Source Firkin
This is the remix of an Openclipart clipart called "Maze" uploaded by "any_ono_mous".Thanks.This is a seamless pattern of a maze.
Source Yamachem
Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.
Source Atle Mo
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
Abstract Tiled Background Extended 6
Source GDJ
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
The name is totally random, but hey, it sounds good.
Source Atle Mo
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin