The image depicts a seamless pattern of a fishnet with a plenty of fish.It may be a lucky charm for fishermen.
Source Yamachem
Prismatic Geometric Pattern Background No Black
Source GDJ
It looks like a polished stone surface to me. Download it for free, as always.
Source V. Hartikainen
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Heavily remixed from a drawing that was uploaded to Pixabay by ractapopulous
Source Firkin
New paper pattern with a slightly organic feel to it, using some thin threads.
Source Atle Mo
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
A rusty grunge background for websites. Feel free to use it in your site's theme.
Source V. Hartikainen
Geometric triangles seem to be quite hot these days.
Source Pixeden
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
An alternative colour scheme to the original seamless pattern.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Prismatic Hexagonalist Pattern No Background
Source GDJ
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
This light yellow background pattern consists of an irregular pattern of spots. Here's a light background pattern with yellowish tint.
Source V. Hartikainen
Prismatic Groovy Concentric Background No Black
Source GDJ
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
Dark wooden pattern, given the subtle treatment. based on texture from Cloaks.