Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
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
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
Derived from a drawing in 'The Murmur of the Shells', Samuel Cowen, 1879.
Source Firkin
This is the remix of "Colorful Floral Pattern Background 3" uploaded by "GDJ". Thanks.
Source Yamachem
Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
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
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
This was submitted in a beige color, hence the name. Now it’s a gray paper pattern.
Source Konstantin Ivanov
This one looks like a cork panel. Feel free to use it as a tiled background on your blog or website.
Source V. Hartikainen
A simple bump filter made upon request at irc #inkscape at freenode. Made a screen capture of the making here: https://youtu.be/TGAWYKVLxQw
Source Lazur URH
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight