The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Subtle scratches on a light gray background.
Source Andrey Ovcharov
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
All good things come in threes, so I give you the third in my little concrete wall series.
Source Atle Mo
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
This is a seamless pattern of a woody texture.The original image is here:https://pixabay.com/ja/users/ClassicallyPrinted-1302233/
Source Yamachem
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
Actually, there's no clouds in it, but I think it looks quite nice.
Source V. Hartikainen
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
One can never have too few rice paper patterns, so here is one more.
Source Atle Mo
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight