Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
From a drawing in 'Royal Ramsgate', James Simson, 1897.
Source Firkin
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
White circles connecting on a light gray background.
Source Mark Collins
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
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
Prismatic Triangular Seamless Pattern III With Background
Source GDJ
A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen
Embossed lines and squares with subtle highlights.
Source Alex Parker
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
This is so subtle: We’re talking 1% opacity. Get your squint on!
Source Atle Mo
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman
By popular request, an outline version of the pentagon pattern.
Source Atle Mo
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Seamless tile drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
With a name like this, it has to be hot. Diagonal lines in light shades.
Source Isaac
Just like the black maze, only in light gray. Duh.
Source Peax