From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
Non-seamless pattern drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
A dark gray, sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
A seamless pattern with wide vertical stripes colored in pale yellow.
Source V. Hartikainen
Pixel by pixel, sharp and clean. Very light pattern with clear lines.
Source M.Ashok
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Zero CC tileable pine bark texture, photographed and made by me. CC0
Source Sojan Janso
Traced from a drawing in 'Household Stories from the Collection of the Brothers Grimm', Wilhelm Carl Grimm , 1882.
Source Firkin
A light gray fabric pattern with faded vertical stripes.
Source V. Hartikainen
The tile can be had by selecting the rectangle in Inkscape and using shift+alt+i. Remixed from a drawing in 'Flowers of Song', Frederick Weatherly, 1895.
Source Firkin
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.
Source Alex Parker
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!
Source Dertig Media
Remixed from an image on Pixabay uploaded by Prawny
Source Firkin
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim