A slightly grainy paper pattern with small horizontal and vertical strokes.
Source Atle Mo
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
More in the paper realm, this time with fibers.
Source Jorge Fuentes
From an image on opengameart.org shared by rubberduck.
Source Firkin
Prismatic Triangular Background Design Mark II 5
Source GDJ
White circles connecting on a light gray background.
Source Mark Collins
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne