Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
A chequerboard pattern with a fruit theme. The fruits are from a posting by inkscapeforum.it.
Source Firkin
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Background formed from the original with an emboss effect.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A dark striped seamless pattern suitable for use as a background on websites.
Source V. Hartikainen
A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
A free web background image with a seamless concrete-like texture and an Indian-red color.
Source V. Hartikainen
Dark blue concrete wall with some small dust spots.
Source Atle Mo
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
A lovely light gray pattern with stripes and a dash of noise.
Source V. Hartikainen
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
Sharp but soft triangles in light shades of gray.
Source Pixeden
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
The classic notebook paper with horizontal stripes.
Source Are Sundnes
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
A fun-looking elastoplast/band-aid pattern. A hint of orange tone in this one.
Source Josh Green
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Prismatic Abstract Geometric Background 4
Source GDJ
Number five from the same submitter, makes my job easy.
Source Dima Shiper
Gold Triangular Seamless Pattern No Background
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin