From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A very slick dark rubber grip pattern, sort of like the grip on a camera.
Source Sinisha
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
Clean and crisp lines all over the place. Wrap it up with this one.
Source Dax Kieran
Number five from the same submitter, makes my job easy.
Source Dima Shiper
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
On a large canvas you can see it tiling, but used on smaller areas, it’s beautiful.
Source Paul Phönixweiß
Remixed from a drawing that was uploaded to Pixabay by captenpub.
Source Firkin
The original enhanced with one of Inkscapes's filters.
Source Firkin
A seamless pale yellow paper background with a pattern of animal tracks.
Source V. Hartikainen
A free grid paper background pattern for using on web sites.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Floral patterns might not be the hottest thing right now, but you never know when you need it!
Source Lauren
This one is quite simple in design, it consists of vertical stripes layered on top of a seamless texture.
Source V. Hartikainen
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
Seamless pattern made from a tile that can be obtained in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A free seamless background pattern for use on websites.
Source V. Hartikainen
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Another fairly simple design drawn in Paint.net and vectorized in Inkscape.
Source Firkin