Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Zero CC tileable wood texture, made by me procedurally in Neo Texture Edit.
Source Sojan Janso
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
By popular request, an outline version of the pentagon pattern.
Source Atle Mo
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
From a drawing in 'Heroes of North African Discovery', Nancy Meugens, 1894.
Source Firkin
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
As simple and subtle as it gets. But sometimes that’s just what you want.
Source Designova
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
The name alone is awesome, but so is this sweet dark pattern.
Source Federica Pelzel
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
I’m not going to lie – if you submit something with the words Norwegian and Rose in it, it’s likely I’ll publish it.
Source Fredrik Scheide
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Remixed from a drawing in 'Kulturgeschichte der Deutschen im Mittelalter' Franz von Loeher, 1891. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo