Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
Prismatic Groovy Concentric Background 5
Source GDJ
Prismatic Triangular Background Design Mark II 5
Source GDJ
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
Seamless pattern inspired by a drawing on Pixabay. To get the tile this is formed from, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A fun-looking elastoplast/band-aid pattern. A hint of orange tone in this one.
Source Josh Green
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin