A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
Prismatic Abstract Geometric Background 4
Source GDJ
This light blue background pattern is quite pleasing to the eye, it consists of a tiny rough grid pattern, which is seamless by design. That's it, if you like the color, you can use this seamless pattern in a web design without making any further modifications to it.
Source V. Hartikainen
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
Zero CC tileable brick texture, photographed and made by me. CC0
Source Sojan Janso
Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
A background pattern with green vertical stripes. A new striped background pattern. This time a green one.
Source V. Hartikainen
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Zero CC tillable hard cover red book with X shape marks. Scanned and made by me.
Source Sojan Janso
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A free repetitive background with a dark concrete wall like texture. This one may be used in dark web site designs.
Source V. Hartikainen
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
Seamless Background For Websites. It has a texture similar to cork-board.
Source V. Hartikainen
Abstract Tiled Background Extended 12
Source GDJ
This beige background pattern resembles a concrete wall with engravings or something similar to it.
Source V. Hartikainen
Prismatic Abstract Geometric Background 5
Source GDJ
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Derived from an image that was uploaded to Pixabay by mdmelo.
Source Firkin