Geometric triangles seem to be quite hot these days.
Source Pixeden
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A seamless pattern with wide vertical stripes colored in pale yellow.
Source V. Hartikainen
Prismatic Snowflakes Pattern No Background
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless tessellation pattern. To get the tile this is formed from, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!
Source V. Hartikainen
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
He influenced us all. “Don’t be sad because it’s over. Smile because it happened.”
Source Atle Mo
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
Derived from an image that was uploaded to Pixabay by pugmom40
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Sometimes you just need the simplest thing.
Source Fabricio
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin