A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
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
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
A free web background image with a seamless concrete-like texture and an Indian-red color.
Source V. Hartikainen
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
A floral background formed from numerous clones of flower 117.
Source Firkin
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
This background pattern contains a texture of yellow wood planks. I think it looks quite original.
Source V. Hartikainen
The image depicts polka dot seamless pattern.
Source Yamachem
Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
This metal background pattern resembles a metal plate with rivets. Solid rivets on a metal plate.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Prismatic Abstract Geometric Background 4
Source GDJ