From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
You know I’m a sucker for these. Well-crafted paper pattern.
Source Mihaela Hinayon
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
Prismatic Polka Dots 3 No Background
Source GDJ
Here's a bluish gray striped background pattern for use on web sites.
Source V. Hartikainen
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Just like your old suit, all striped and smooth.
Source Alex Berkowitz
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Inspired by a pattern found in 'A General History of Hampshire, or the County of Southampton, including the Isle of Wight', Bernard Woodwood, 1861
Source Firkin
Colorful Floral Background 3 No Black
Source GDJ
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
This was formed by distorting an image of a background on Pixabay.
Source Firkin
A black tile-able background with paper-like texture.
Source V. Hartikainen
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
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
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
I’m guessing this is related to the Sony Vaio? It’s a nice pattern no matter where it’s from.
Source Zigzain
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Here's a repeatable texture that resembles a light green concrete wall or something similar.
Source V. Hartikainen