The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Here's a dark background pattern that contains a steel grid pattern as a texture. Use it as a website background or for other purposes. It's free!
Source V. Hartikainen
The image is a seamless pattern of a fishnet.
Source Yamachem
A dark metallic background with a pattern of stamped dots. Here's a dark "metallic" background pattern for you.
Source V. Hartikainen
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
Sort of reminds me of those old house wallpapers.
Source Tish
Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
The image depicts a seamless pattern of Japanese Edo pattern called "kikkou-matsu" or "亀甲松" meaning " tortoiseshell-pinetree".The real pinetree is like this: https://jp.pinterest.com/pin/500744052301065077/
Source Yamachem
Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber