Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
The image depicts a seamless pattern of a snow crystal.I referred to a book called ”sekka-zusetsu” or "雪華図説" which means an illustrated explanation about snow crystals.This book was published in 1832 (天保3年) or Edo period.For more about "雪華図説",see here:dl.ndl.go.jp/info:ndljp/pid/2536975
Source Yamachem
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
Adapted from an image that was uploaded to Pixabay by Anerma.
Source Firkin
Inspired by a 1930s wallpaper pattern I saw on TV.
Source Firkin
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
Prismatic Groovy Concentric Background 3
Source GDJ
A re-make of the Gradient Squares pattern.
Source Dimitar Karaytchev
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Seamless SVG vector and JPG backgrounds with faded diagonal stripes. The colors are editable.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
These dots are already worn for you, so you don’t have to.
Source Matt McDaniel
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
Bumps, highlight and shadows – all good things.
Source Badhon Ebrahim