A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Prismatic Triangular Background Design Mark II 5
Source GDJ
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
Retro Circles Background 4 No Black
Source GDJ
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen
Remixed from an image that was uploaded to Pixabay by KirstenStar
Source Firkin
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Alternative colour scheme for the original floral pattern.
Source Firkin
From a drawing in 'Jardyne's Wife', Charles Wills, 1891.
Source Firkin
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
Feel free to download and use it, or see the rest of the dark background patterns that I have made. Anyway, I hope you will find something that you like.
Source V. Hartikainen
One can never have too few rice paper patterns, so here is one more.
Source Atle Mo
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
A free green background pattern with a pattern of rhombuses on a seamless texture. Feel free to use it as a tiled background image on your web site.
Source V. Hartikainen
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens