You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
A free seamless background image with abstract texture of green "curtain".
Source V. Hartikainen
Prismatic Chevrons Pattern 5 With Background
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
Seamless pattern made from a tile that can be obtained in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A pattern drawn in Paint.net and vectorized in Inkscape.
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by susanlu4esm
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica
Produced using the clouds, flames and glass blocks plug-ins in Paint.net and the resulting .PNG vectorised with Vector Magic.
Source Firkin
This is a remix of "geometrical pattern 01".
Source Yamachem
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
A repeating graphic with ancient pattern. I came up with this name/title at last minute, so you may find that there is very little of ancientness in this pattern after all.
Source V. Hartikainen
Sharp but soft triangles in light shades of gray.
Source Pixeden
The Grid. A digital frontier. I tried to picture clusters of information as they traveled through the computer.
Source Haris Šumić
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc