This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
The tile for this is based on a repeating unit close to a design on Pixabay. It can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
This is the remix of "Tileable Wave Pattern 2" uploaded by "Arvin61r58".Thanks.I added a wire-mesh fence seamless pattern as a lower layer.
Source Yamachem
From a drawing in 'A Rolling Stone. A tale of wrongs and revenge', John Hartley, 1878.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
A free light orange brown wallpaper with vertical stripes designed for use as a tiled background on websites. An yet another background pattern with vertical stripes.
Source V. Hartikainen
Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
A seamless pattern recreated from an image on Pixabay. It is reminiscent of parquet flooring and is formed from a square tile, which can be recovered in Inkscape by selecting the ungrouped rectangle and using shift-alt-I together.
Source Firkin
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
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
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin
All good things come in threes, so I give you the third in my little concrete wall series.
Source Atle Mo
A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
Colorful Floral Background 3 No Black
Source GDJ
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin