A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
CC0 remixed from a drawing. Walter Crane, 1914, Firkin.
Source SliverKnight
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Pattern Background, Texture, Photoshop Structure style CC0 texture.
Source Darkmoon1968
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
White fabric looking texture with some nice random wave features.
Source Hendrik Lammers
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
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
Same classic 45-degree pattern, dark version.
Source Luke McDonald
Black brick wall pattern. Brick your site up!
Source Alex Parker
Wasn't satisfied with the original's colouring. Too much component transfer and colormatrixes yet the results are lacking a bit. So this time it is a simple black to transparent fade, making it possible remixing easily once there will be other blending modes supported as well. Probably in inkscape 0.92.
Source Lazur URH
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
A seamless pattern formed from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A background pattern with blue on white vertical stripes.
Source V. Hartikainen
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
A bit strange this one, but nice at the same time.
Source Diogo Silva
Black paper texture, based on two different images.
Source Atle Mo
Based from Design Kindle