Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
A free seamless background with pink spots.
Source V. Hartikainen
Sharp but soft triangles in light shades of gray.
Source Pixeden
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Alternative colour scheme to the original.
Source Firkin
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
The image is a design of blue glass.How about using it as background image?
Source Yamachem
A seamless background tile of aged paper with shabby look.
Source V. Hartikainen
Remixed from a JPG that was uploaded to Pixabay by susanlu4esm
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
Remixed from an image that was uploaded to Pixabay by KirstenStar
Source Firkin
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
Kaleidoscope Prismatic Abstract No Background
Source GDJ
Prismatic Groovy Concentric Background 3
Source GDJ
A seamless pattern formed from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Geometric Pattern Background 2
Source GDJ
Alternative colour scheme for the original floral pattern.
Source Firkin
Remixed from a drawing in 'Kulturgeschichte der Deutschen im Mittelalter' Franz von Loeher, 1891. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Zero CC tileable hard cover red book, scanned and made by me. CC0
Source Sojan Janso