Here's a brown background pattern with subtle stripes. I hope you'll like the color. If not, feel free to change it using an image editor, if you know how of course. Personally, I'm using GIMP to create these backgrounds.
Source V. Hartikainen
Background Wall, Art Abstract, Star Well & CC0 texture.
Source Ractapopulous
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Some dark 45 degree angles creating a nice pattern. Huge.
Source Dark Sharp Edges
From a drawing in 'Kingsdene', Maria Fetherstonehaugh, 1878.
Source Firkin
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
Redrawn based on a drawing in 'По Сѣверо-Западу Россіи' Konstantin Sluchevsky, 1897.
Source Firkin
Prismatic Polyskelion Pattern No Background
Source GDJ
Sharp but soft triangles in light shades of gray.
Source Pixeden
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
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
From a drawing in 'La Principauté de Liège et les Pays-Bas au XVIe siècle', Société des Bibliophiles Liégeois ,1887.
Source Firkin
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
Inspired by a drawing in 'Poems', James Smith, 1881.
Source Firkin
This is the remix of "polka dot seamless pattern".The image depicts polka dot seamless pattern.
Source Yamachem
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
8 by 8 pixels, and just what the title says.
Source pixilated