A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
Black brick wall pattern. Brick your site up!
Source Alex Parker
A dark gray, sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Remixed from a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
A comeback for you: the popular Escheresque, now in black.
Source Patten
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a drawing in 'Incidents on a Journey through Nubia to Darfoor', F. Ensor, 1891.
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Zero CC tileable hard cover red book, scanned and made by me. CC0
Source Sojan Janso
This pattern comes in orange, and it looks as if it is "made of glass".
Source V. Hartikainen
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
Zero CC bark from fur tree tileable texture, photographed and made by me. CC0
Source Sojan Janso
Vector version of a png that was uploaded to Pixabay by pencilparker
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
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
Colour version of the original pattern inspired by the front cover of 'Old and New Paris', Henry Edwards, 1894.
Source Firkin