This background pattern contains a texture of yellow wood planks. I think it looks quite original.
Source V. Hartikainen
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
A comeback for you: the popular Escheresque, now in black.
Source Patten
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
A seamless background texture of old cardboard.
Source V. Hartikainen
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
Prismatic Geometric Pattern Background No Black
Source GDJ
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
Fix and cc0 to get the tile this is based on.
Source SliverKnight
Abstract Stars Geometric Pattern Prismatic No Background
Source GDJ
The tile this is based on was adapted from an image that was uploaded to Pixabay by frolicsomepl. It can be had in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Pass parameters to the URL or edit the source code variables to configure the graph paper for the division desired.
Source JayNick