A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Seamless Green Tile Background
Source V. Hartikainen
An alternative colour scheme to the original seamless pattern.
Source Firkin
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
A cute x, if you need that sort of thing.
Source Juan Scrocchi
Orange-red pattern for tiled backgrounds.
Source V. Hartikainen
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A pattern derived from repeating unit cells each derived from part of a mosaic in paint.net. The starting point for the mosaic was a picture of some prawns!
Source Firkin
A background pattern with blue on white vertical stripes.
Source V. Hartikainen
The image is the remix of "wire-mesh fence seamless pattern" .This is a more minute version of it.Sorry for the file size.Using path>difference in Inkscape, I will cut out any silhouette from this pattern and create a "meshed silhouette".
Source Yamachem
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
Prismatic Abstract Geometric Background 4
Source GDJ
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
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