Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Derived from an image that was uploaded to Pixabay by pugmom40
Source Firkin
Almost like little fish shells, or dragon skin.
Source Graphiste
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
A seamless pattern formed from background pattern 102
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics
A dark metallic background with a pattern of stamped dots. Here's a dark "metallic" background pattern for you.
Source V. Hartikainen
All good things come in threes, so I give you the third in my little concrete wall series.
Source Atle Mo
Submitted by DomainsInfo – wtf, right? But hey, a free pattern.
Source DomainsInfo
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Redrawn based on a drawing in 'По Сѣверо-Западу Россіи' Konstantin Sluchevsky, 1897.
Source Firkin
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
Remixed from an image on Pixabay, the original having been uploaded by darkmoon1968.
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
Inspired by a design found in 'Konstantinápolyi emlékeim', Miklos Chriszto, 1893.
Source Firkin
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Prismatic Curved Diamond Pattern No Background
Source GDJ
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica