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
Produced using the clouds, flames and glass blocks plug-ins in Paint.net and the resulting .PNG vectorised with Vector Magic.
Source Firkin
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
The image depicts meshed silhouettes of various things.The original image is an OCAL clipart called "Enter FOSSASIA 2016 #IoT T-shirt Design Contest" uploaded by "openclipart".Thanks.
Source Yamachem
Non-seamless pattern drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Prismatic Chevrons Pattern 5 With Background
Source GDJ
Prismatic Groovy Concentric Background 4
Source GDJ
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Number 3 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
The image is a remix of "edo pattern-samekomon".I changed the color of dots from black to white and added BG in light-brown.
Source Yamachem
Prismatic 3D Isometric Tessellation Pattern 6
Source GDJ