Checkered Light Emboss #280
 Grid  CC BY-SA 3.0

Sort of like the Photoshop transparent background, but better!

Source Alex Parker

 More Textures
Prismatic Geometric Pattern Variation 2 With Background #471
 Noise  CC 0

Prismatic Geometric Pattern Variation 2 With Background

Source GDJ

Vintage pattern #2296
 Brown  CC 0

Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Interlocking pattern 3 (colour 2) #2405
 Grid  CC 0

A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.

Source Firkin

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

Abstract Geometric Monochrome Pattern Prismatic No Background #385
 Noise  CC 0

Abstract Geometric Monochrome Pattern Prismatic No Background

Source GDJ

Background pattern 273 #2042
 Dark  CC 0

Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.

Source Firkin

Decorative divider 188 #2521
 Dark  CC 0

From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.

Source Firkin

Background pattern 259 (colour 3) #2130
 Colorful  CC 0

Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

Background pattern pink #1948
 Pink  CC 0

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

Source Firkin

Seamless Colorful Floral Pattern Background #256
 Fabric  CC 0

PDP

Source GDJ

Background pattern 235 (colour 2) #2254
 Blue  CC 0

To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.

Source Firkin