Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
A very dark asfalt pattern based off of a photo taken with my iPhone.
Source Atle Mo
Formed from decorative divider 184 in paint.net. Vectorised with Vector Magic.
Source Firkin
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Light honeycomb pattern made up of the classic hexagon shape.
Source Federica Pelzel
Here's a bluish gray striped background pattern for use on web sites.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A repeating background for websites with a texture of black groove stripes.
Source V. Hartikainen
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
Submitted in a cream color, but you know how I like it.
Source Devin Holmes
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Background pattern made in "Grunge-Like" style. Available in both SVG and JPG formats. Edit to your needs then click the download button.
Source V. Hartikainen
Clean and crisp lines all over the place. Wrap it up with this one.
Source Dax Kieran