You may use it as is, or modify it as you like.
Source V. Hartikainen
Original seamless pattern with an Inkscape filter.
Source Firkin
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
Prismatic Abstract Background Design
Source GDJ
This is a more minute version of "fishnet 01".The image depicts a seamless pattern of a fishnet with a plenty of fish.It may be a lucky charm for fishermen.
Source Yamachem
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A tile-able background for websites with paper-like texture and a grid pattern layered on top of it.
Source V. Hartikainen
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
A background tile for web with abstract repeating texture of dark "stone wall".
Source V. Hartikainen
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin