This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Remix from a drawing in 'Ostatnie chwile powstania styczniowego', Zygmunt Sulima, 1887.
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Seamless Prismatic Pythagorean Line Art Pattern No Background. 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 dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo
A seamless pattern with green and yellow diagonal lines on top of a white dotted background.
Source V. Hartikainen
Inspired by a drawing seen in 'City of Liverpool', James Picton, 1883.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Same classic 45-degree pattern, dark version.
Source Luke McDonald
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
I asked Gjermund if he could make a pattern for us – result!
Source Gjermund Gustavsen
Prismatic Groovy Concentric Background 2
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
This was formed by distorting an image of a background on Pixabay.
Source Firkin