Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
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
From a drawing in 'Friend or Fortune? The story of a strange year', Robert Overton, 1897.
Source Firkin
Seamless Light Background Texture.
Source V. Hartikainen
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
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
A re-make of the Gradient Squares pattern.
Source Dimitar Karaytchev
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
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
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Zero CC tileable yellow craft paper; scanned and made by me. CC0
Source Sojan Janso
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
Source Badhon Ebrahim
Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.
Source Alex Parker
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
Black brick wall pattern. Brick your site up!
Source Alex Parker
Seamless Dark Grunge Texture. Here's a new grunge texture for use as a background.
Source V. Hartikainen
Remixed from a drawing in 'Works. Popular edition', John Ruskin, 1886.
Source Firkin