Sharp pixel pattern, just like the good old days.
Source Paridhi
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
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
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Dark blue concrete wall with some small dust spots.
Source Atle Mo
Submitted by DomainsInfo – wtf, right? But hey, a free pattern.
Source DomainsInfo
The Grid. A digital frontier. I tried to picture clusters of information as they traveled through the computer.
Source Haris Šumić
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
A version without colours blended together to give a different look.
Source Firkin
A frame using leaves from an image that was uploaded to Pixabay by mayapujiati
Source Firkin
Green Web Background, Seamless tile.
Source V. Hartikainen
This is sort of fresh, but still feels a bit old school.
Source Martuchox
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
A bit simplified version. Although it could be edited out to be simpler. Anyway, this time the tiling is converted to a pattern fill -which is using clipping for the tile's edges.
Source Lazur URH
Might not be super subtle, but quite original in its form.
Source Alex Smith
Another fairly simple design drawn in Paint.net and vectorized in Inkscape.
Source Firkin
A lovely light gray pattern with stripes and a dash of noise.
Source V. Hartikainen
An alternative colour scheme to the original seamless pattern.
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
If you need a green background for your blog/website, try this one. Remember that Green Striped Background is seamlessly tileable.
Source V. Hartikainen
A seamless pale yellow paper background with a pattern of animal tracks.
Source V. Hartikainen