This is so subtle: We’re talking 1% opacity. Get your squint on!
Source Atle Mo
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
A dark brown fabric-like background texture with seamless pattern of winding stripes.
Source V. Hartikainen
A seamless pattern created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Remixed from a drawing in 'Analecta Eboracensia', Thomas Widdrington, 1897.
Source Firkin
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
Subtle grunge and many little pluses on top.
Source Atle Mo
Remixed from a JPG that was uploaded to Pixabay by Osckar
Source Firkin
This light blue background pattern is quite pleasing to the eye, it consists of a tiny rough grid pattern, which is seamless by design. That's it, if you like the color, you can use this seamless pattern in a web design without making any further modifications to it.
Source V. Hartikainen
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
A heavy hitter at 400x400px, but lovely still.
Source Breezi
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
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
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
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
The image depicts polka dot seamless pattern.
Source Yamachem