Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A nice and simple white rotated tile pattern.
Source Another One
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
The following free background pattern has glossy diagonal stripes as a texture to it, and it's colored in a light blue gray color. This background pattern is suitable for using in web design or any other graphic design projects. This applies to all background patterns here.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
Seamless Background For Websites. It has a texture similar to cork-board.
Source V. Hartikainen
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Plywood Web Background background image for use in web design.
Source V. Hartikainen
Prepared mostly as a raster in Paint.net and vectorised.
Source Firkin
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
The image depicts a seamless pattern of a tortoise in tortoiseshell (hexagon).
Source Yamachem
The original enhanced with some gradients.
Source Firkin
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
From an image on opengameart.org shared by rubberduck.
Source Firkin
The base gradient edited so now more details are rendered.
Source Lazur URH
From a drawing in 'An Old Maid's Love. A Dutch tale told in English', Maarten Maartens, 1891.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Geometric triangles seem to be quite hot these days.
Source Pixeden