Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
The following repeating website background is colored in a blue gray color and resembles a concrete wall or something similar to it.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
This was submitted in a beige color, hence the name. Now it’s a gray paper pattern.
Source Konstantin Ivanov
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Alternative colour scheme to the original.
Source Firkin
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
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
Abstract Geometric Monochrome Pattern Prismatic No Background
Source GDJ
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel
Remixed from a drawing in 'Works. Popular edition', John Ruskin, 1886.
Source Firkin
Colour version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Zero CC tileable ground (#2) cracked, crackled texture, made by me. CC0
Source Sojan Janso