This one is quite simple in design, it consists of vertical stripes layered on top of a seamless texture.
Source V. Hartikainen
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
Pattern formed from simple shapes. Black version.
Source Firkin
Black And White Floral Pattern Background from PDP.
Source GDJ
The image is a remix of "edo pattern-samekomon".I changed the color of dots from black to white and added BG in light-yellow.
Source Yamachem
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
Prismatic Abstract Geometric Background 4
Source GDJ
Psychedelic Geometric Background No Black
Source GDJ
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Prismatic Abstract Background Design
Source GDJ
Here's an yet another seamless note paper texture for use as a background on websites.
Source V. Hartikainen
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
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
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
He influenced us all. “Don’t be sad because it’s over. Smile because it happened.”
Source Atle Mo
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a PNG that was uploaded to Pixabay by k_jprather
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin