Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
A seamless striped fabric-like texture colored in a dark reddish brown color.
Source V. Hartikainen
A bit of scratched up grayness. Always good.
Source Dmitry
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
A seamless pattern formed from a rectangular tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Based on several public domain drawings on Wikimedia Commons. This was formed from a rectangular tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i
Source Firkin
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
Embossed lines and squares with subtle highlights.
Source Alex Parker
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
To get the tile this is based on select the rectangle in Inkscape and use 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
Prismatic Snowflakes Pattern No Background
Source GDJ
A free seamless texture of reptile skin colored in a dark brown color. As always, you may use it as a repeated background image in your web design works, or for any other purposes.
Source V. Hartikainen
A bit simplified version. Although it could be edited out to be simpler. Anyway, this time the tiling is converted to a pattern fill -which is using clipping for the tile's edges.
Source Lazur URH
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
A large pattern with funky shapes and form. An original. Sort of origami-ish.
Source Luuk van Baars