From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
"Beige Stone", Tileable Texture.
Source V. Hartikainen
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
A colourful background drawn originally in paint.net and vectorised in Vector Magic.
Source Firkin
This is the remix of "plant pattern 02".I changed the object color to white and the BG to purple.The image a seamless pattern derived from a weed which I can't identify.The original weed image is from here:jp.pinterest.com/pin/500744052301423641/
Source Yamachem
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
A background pattern with blue on white vertical stripes.
Source V. Hartikainen
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Sharp pixel pattern, just like the good old days.
Source Paridhi
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ
It looks like a polished stone surface to me. Download it for free, as always.
Source V. Hartikainen
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Looks like an old wall. I guess that’s it then?
Source Viahorizon
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
A seamless background of warped stripes on paper.
Source V. Hartikainen
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz