Pixel by pixel, sharp and clean. Very light pattern with clear lines.
Source M.Ashok
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile 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
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
This is a seamless pattern which is derived from a flower petal image.
Source Yamachem
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Black brick wall pattern. Brick your site up!
Source Alex Parker
A colourful background drawn originally in paint.net and vectorised in Vector Magic.
Source Firkin
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
Prismatic Groovy Concentric Background
Source GDJ
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
This background pattern contains a texture of yellow wood planks. I think it looks quite original.
Source V. Hartikainen
Remixed from a drawing in 'Incidents on a Journey through Nubia to Darfoor', F. Ensor, 1891.
Source Firkin