A free seamless background with pink spots.
Source V. Hartikainen
Inspired by a drawing in 'Kulturgeschichte', Freidrich Hellwald, 1896.
Source Firkin
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
A seamless marble-like texture colored in light blue.
Source V. Hartikainen
The classic notebook paper with horizontal stripes.
Source Are Sundnes
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
White circles connecting on a light gray background.
Source Mark Collins
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
A bit strange this one, but nice at the same time.
Source Diogo Silva
You guessed it – looks a bit like cloth.
Source Peax Webdesign
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
The image depicts a seamless pattern of Japanese Edo pattern called "kikkou-matsu" or "亀甲松" meaning " tortoiseshell-pinetree".The real pinetree is like this: https://jp.pinterest.com/pin/500744052301065077/
Source Yamachem
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
Prismatic Chevrons Pattern 5 With Background
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Dark blue concrete wall with some small dust spots.
Source Atle Mo
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
With a name like this, it has to be hot. Diagonal lines in light shades.
Source Isaac
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury