A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
From drawing in 'Musings in Maoriland', Thomas Bracken, 1890.
Source Firkin
Prismatic Triangular Background Design Mark II 5
Source GDJ
Sort of reminds me of those old house wallpapers.
Source Tish
Use shift+alt+i on the selected rectangle in Inkscape to get the tile this is based on
Source Firkin
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
Remixed from a drawing that was uploaded to Pixabay by DavidZydd
Source Firkin
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
A brown seamless wood texture in a form of stripe pattern. The result has turned out pretty well, in my opinion.
Source V. Hartikainen
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
This texture looks like old leather. It should look great as a background on web pages.
Source V. Hartikainen
Clover with background for St. Patrick's Day. Add to a card with a doily, ribbon, a leprechaun or other embellishments.
Source BAJ
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo