From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
Seamless Prismatic Quadrilateral Line Art Pattern No Background
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A version without colours blended together to give a different look.
Source Firkin
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
f you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Fix and cc0 to get the tile this is based on.
Source SliverKnight
Remixed from a drawing in 'Works. Popular edition', John Ruskin, 1886.
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless pattern with green and yellow diagonal lines on top of a white dotted background.
Source V. Hartikainen
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
Lovely pattern with splattered vintage speckles.
Source David Pomfret
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Prismatic Rounded Squares Grid 3 No Background
Source GDJ