A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
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
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Background formed from the original with an emboss effect.
Source Firkin
This background has abstract texture with some similarities to wood.
Source V. Hartikainen
You know I love paper patterns. Here is one from Stephen. Say thank you!
Source Stephen Gilbert
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
ZeroCC tileable wood boards texture, photographed and made by me. CC0
Source Sojan Janso
ZeroCC tileable moss texture, photographed and made by me. CC0
Source Sojan Janso
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
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
A repeating background of beige (or is it more vanilla yellow) textured stripes. One more background with stripes.
Source V. Hartikainen
Not the most creative name, but it’s a good all-purpose light background.
Source Dmitry
A seamless pattern with a unit cell drawn as a bitmap in Paint.net and vectorized in Vector Magic.
Source Firkin
Here's an yet another seamless note paper texture for use as a background on websites.
Source V. Hartikainen
A seamless pattern recreated from an image on Pixabay. It is reminiscent of parquet flooring and is formed from a square tile, which can be recovered in Inkscape by selecting the ungrouped rectangle and using shift-alt-I together.
Source Firkin
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
An alternative colour scheme to the original seamless pattern.
Source Firkin