I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
The image depicts a Japanese Edo pattern called "kanoko or 鹿の子" meaning "fawn" which has a fur with small white spots.
Source Yamachem
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Utilising a bird from s-light and some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Medium gray pattern with small strokes to give a weave effect.
Source Catherine
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
A grayscale fabric pattern with vertical lines of stitch holes.
Source V. Hartikainen
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Zero CC tileable Laminate wood texture, photographed and made by me. CC0
Source Sojan Janso
This seamless web background texture looks like gray stone. It's great for using as a background image on web pages, or on some of their elements. Anyway, I hope you will find use for it.
Source V. Hartikainen
This light yellow background pattern consists of an irregular pattern of spots. Here's a light background pattern with yellowish tint.
Source V. Hartikainen
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki