Prismatic Abstract Background Design
Source GDJ
From a drawing in 'Picturesque New Guinea', J Lindt, 1887.
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
A free background pattern with abstract green tiles.
Source V. Hartikainen
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
A seamless background pattern with impressed gray dots.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i
Source Firkin
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Prismatic Groovy Concentric Background 2
Source GDJ
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
Alternative colour scheme for the original floral pattern.
Source Firkin
Prismatic Hexagonalist Pattern No Background
Source GDJ
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
A cute x, if you need that sort of thing.
Source Juan Scrocchi
A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
Alternative colour scheme for the original floral pattern.
Source Firkin
A new take on the black linen pattern. Softer this time.
Source Atle Mo