Looks as if it's spray painted on the wall. You can be sure that this pattern will seamlessly fill your backgrounds on web pages.
Source V. Hartikainen
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
Oh yes, it happened! A pattern in full color.
Source Atle Mo
Everyone needs some stardust. Sprinkle it on your next project.
Source Atle Mo
A free black metallic background pattern. Here's a new pattern I made that looks metallic.
Source V. Hartikainen
From a drawing in 'An Old Maid's Love. A Dutch tale told in English', Maarten Maartens, 1891.
Source Firkin
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Turn your site into a dragon with this great scale pattern.
Source Alex Parker
Number five from the same submitter, makes my job easy.
Source Dima Shiper
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Lovely pattern with splattered vintage speckles.
Source David Pomfret
Derived from an image that was uploaded to Pixabay by pugmom40
Source Firkin
No, not the band but the pattern. Simple squares in gray tones, of course.
Source Atle Mo
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Nicely executed tiling for an interesting pattern.
Source Ignasi Àvila Padró