The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Pass parameters to the URL or edit the source code variables to configure the graph paper for the division desired.
Source JayNick
A background pattern with a look of rough fabric.
Source V. Hartikainen
Number 5 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i
Source Firkin
A new take on the black linen pattern. Softer this time.
Source Atle Mo
Zero CC tileable brick texture, photographed and made by me. CC0
Source Sojan Janso
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Orange-red pattern for tiled backgrounds.
Source V. Hartikainen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
Nice little grid. Would work great as a base on top of some other patterns.
Source Arno Gregorian
Prismatic Abstract Background Design
Source GDJ
Remixed from a drawing in 'Analecta Eboracensia', Thomas Widdrington, 1897.
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Remixed from a vector adapted from a jpg on Pixabay. The tile this is constructed from can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Remixed from a PNG that was uploaded to Pixabay by gingertea
Source Firkin
A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo