A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A free tileable background colored in off-white (antique white) color.
Source V. Hartikainen
To get the repeating unit, select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Colour version of the original pattern inspired by the front cover of 'Old and New Paris', Henry Edwards, 1894.
Source Firkin
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
Background pattern originally a PNG drawn in Paint.net
Source Firkin
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
From a drawing in 'An Old Maid's Love. A Dutch tale told in English', Maarten Maartens, 1891.
Source Firkin
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
A dark gray, sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
Vector version of a JPG that was uploaded to Pixabay by theasad121
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Prismatic Abstract Geometric Background 4
Source GDJ
Black paper texture, based on two different images.
Source Atle Mo
Based from Design Kindle