The image is a seamless pattern of a fishnet.
Source Yamachem
Sharp but soft triangles in light shades of gray.
Source Pixeden
A repeating background with wood/straw like texture.
Source V. Hartikainen
Abstract Geometric Monochrome Pattern Prismatic No Background
Source GDJ
Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
A seamless paper background texture colored in pale yellow. This seamless texture is ideal for those who need a yellow background image for their website. The texture resembles paper.
Source V. Hartikainen
Sort of reminds me of those old house wallpapers.
Source Tish
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
Prismatic Geometric Pattern Background No Black
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Prismatic Groovy Concentric Background
Source GDJ
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
Seamless Prismatic Quadrilateral Line Art Pattern No Background
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The image depicts a seamless pattern of a Japanese family crest called "chidori" in Japanese .A chidori in Japanese means a plover in English.
Source Yamachem
Tiny circle waves, almost like the ocean.
Source Sagive
Remixed from a PNG that was uploaded to Pixabay by VictorianLady
Source Firkin
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
A free pink background pattern.
Source V. Hartikainen