Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
A free seamless background pattern for use on websites.
Source V. Hartikainen
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
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
Pass parameters to the URL or edit the source code variables to configure the graph paper for the division desired.
Source JayNick
Remixed from a drawing in 'Incidents on a Journey through Nubia to Darfoor', F. Ensor, 1891.
Source Firkin
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
Classic vertical lines, in all its subtlety.
Source Cody L
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Prismatic Hypnotic Pattern No Background
Source GDJ
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
Seamless Prismatic Geometric Pattern With Background
Source GDJ
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin