Black brick wall pattern. Brick your site up!
Source Alex Parker
Feel free to download and use it, or see the rest of the dark background patterns that I have made. Anyway, I hope you will find something that you like.
Source V. Hartikainen
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
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.
Source Firkin
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Colourful background achieved with gradient fills.
Source Firkin
Has nothing to do with toast, but it’s nice and subtle.
Source Pippin Lee
An abstract texture of water. It's not perfect, but will do. You may download if you like it.
Source V. Hartikainen
Remixed from a drawing in 'Works. Popular edition', John Ruskin, 1886.
Source Firkin
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
Prismatic Curved Diamond Pattern 3 No Background
Source GDJ
This was formed by distorting an image of a background on Pixabay.
Source Firkin
He influenced us all. “Don’t be sad because it’s over. Smile because it happened.”
Source Atle Mo
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin