Some rectangles, a bit of dust and grunge, plus a hint of concrete.
Source Atle Mo
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
From a drawing in 'A Guide to the Guildhall of the City of London', John Baddeley, 1898.
Source Firkin
A slightly grainy paper pattern with small horizontal and vertical strokes.
Source Atle Mo
From a drawing in 'Bond Slaves. The story of a struggle.', Isabella Varley, 1893.
Source Firkin
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
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
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
From a drawing in 'An Old Maid's Love. A Dutch tale told in English', Maarten Maartens, 1891.
Source Firkin