Mostly just mucked about with the colours and made one of the paths in the lead frame opaque. The glass remains transparent.
Source Firkin
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
Prismatic Triangular Background Design Mark II 5
Source GDJ
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
A nice and simple gray stucco material. Great on its own, or as a base for a new pattern.
Source Bartosz Kaszubowski
From a drawing in 'Real Sailor-Songs', John Ashton, 1891.
Source Firkin
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
Continuing the geometric trend, here is one more.
Source Mike Warner
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
Derived from an image that was uploaded to Pixabay by mdmelo.
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic
Source Firkin
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
We have some linen patterns here, but none that are stressed. Until now.
Source Jordan Pittman
This pattern comes in orange, and it looks as if it is "made of glass".
Source V. Hartikainen
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
A comeback for you: the popular Escheresque, now in black.
Source Patten
Remix from a drawing in 'Ostatnie chwile powstania styczniowego', Zygmunt Sulima, 1887.
Source Firkin
Clean and crisp lines all over the place. Wrap it up with this one.
Source Dax Kieran