Light Aluminum@2X #305
 Wall  CC BY-SA 3.0

Used correctly, this could be nice. Used in a bad way, all hell will break loose.

Source Atle Mo

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Brushed Alum Dark@2X #66
 Dark  CC BY-SA 3.0

Because I love dark patterns, here is Brushed Alum in a dark coating.

Source Tim Ward

Retro Squares Background #414
 Noise  CC 0

Retro Squares Background

Source GDJ

Background pattern blue #1949
 Blue  CC 0

To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Prismatic Curved Diamond Pattern 7 No Background@2X #548
 Noise  CC 0

Prismatic Curved Diamond Pattern 7 No Background

Source GDJ

Background pattern 225 #2327
 Colorful  CC 0

Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.

Source Firkin

Part of Bayeux Tapestry 4 #2446
 Noise  CC 0

From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.

Source Firkin

Carbon Fiber Big #326
 Carbon  CC BY-SA 3.0

Bigger is better, right? So here you have some large carbon fiber.

Source Factorio.us Collective

Background pattern 226 (colour 4) #2319
 Green  CC 0

A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.

Source Firkin

Sports car pattern 2 #2441
 Colorful  CC 0

A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Background pattern 5 #224
 Noise  CC 0

A pattern drawn in Paint.net and vectorized in Inkscape.

Source Firkin

Background pattern 252 (colour 5) #2158
 Light  CC 0

Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.

Source Firkin