This light blue background pattern is quite pleasing to the eye, it consists of a tiny rough grid pattern, which is seamless by design. That's it, if you like the color, you can use this seamless pattern in a web design without making any further modifications to it.
Source V. Hartikainen
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The image depicts polka dot seamless pattern.
Source Yamachem
A large pattern with funky shapes and form. An original. Sort of origami-ish.
Source Luuk van Baars
A seamless gray background texture suitable for use on websites. To me, it has the look of stone. Feel free to modify it to meet your needs (by making it a bit lighter or darker, for example).
Source V. Hartikainen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
A seamless background colored in pale orange. It has a paper like texture with diagonal grid pattern.
Source V. Hartikainen
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
The image depicts a Japanese Edo pattern called "kanoko or 鹿の子" meaning "fawn" which has a fur with small white spots.
Source Yamachem
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo