Subtle Orange Emboss@2X #98
 Light  CC BY-SA 3.0

A hint of orange color, and some crossed and embossed lines.

Source Adam Anlauf

 More Textures
Background pattern 236 #2249
 Dark  CC 0

Seamless pattern the basic tile for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

Retro Circles Background 8 #435
 Dark  CC 0

Retro Circles Background 8

Source GDJ

Background pattern 314 (colour 3) #1837
 Green  CC 0

The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

White Paperboard@2X #375
 Fabric  CC BY-SA 3.0

Could be paper, could be a Polaroid frame – up to you!

Source Chaos

Prismatic Isometric Cube Wireframe Pattern No Background@2X #500
 Light  CC 0

Prismatic Isometric Cube Wireframe Pattern No Background

Source GDJ