Here's a new paper-like background for free use on personal and commercial projects (this applies to all background patterns here).
Source V. Hartikainen
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
Submitted by DomainsInfo – wtf, right? But hey, a free pattern.
Source DomainsInfo
Prismatic Abstract Geometric Background derived from an image on Pixabay.
Source GDJ
Non-seamless pattern drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Prismatic Curved Diamond Pattern 3 No Background
Source GDJ
Background formed from the original with an emboss effect
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Continuing the geometric trend, here is one more.
Source Mike Warner
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
This is so subtle: We’re talking 1% opacity. Get your squint on!
Source Atle Mo
Zero CC tileable hard cover green book, scanned and made by me. CC0
Source Sojan Janso
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
Prismatic Polka Dots 3 No Background
Source GDJ
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.
Source Alex Parker
Prismatic Groovy Concentric Background 2 No Black
Source GDJ