Based on an image that was uploaded to Pixabay by devanath
Source Firkin
Seamless Prismatic Quadrilateral Line Art Pattern No Background
Source GDJ
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
An abstract web texture of a polished blue stone (or does it look more like ice).
Source V. Hartikainen
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless pattern based on a tile that can be achieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
Turn your site into a dragon with this great scale pattern.
Source Alex Parker
Remixed from a drawing in 'A Child of the Age', Francis Adams, 1894.
Source Firkin
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Fix side and a seamless pattern formed from circles.
Source SliverKnight
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Prismatic Snowflakes Pattern 3 No Background
Source GDJ
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Non-seamless pattern drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
A free pink background pattern.
Source V. Hartikainen