Wavy background #2022
Blue CC 0CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
More Textures
Tessellation 16 (colour 4) #2212
Green CC 0The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
3D Wood #1475
Wood CC 0Basket Fibers, Basket Texture, Braid Background style CC0 texture.
Source 1A-Photoshop
Geometric pattern #2003
Grid CC 0A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Light Grey Floral Motif@2X #345
Wall CC BY-SA 3.0Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
Carpet seamless texture 3 #2553
Wall CC 0From an image on opengameart.org shared by rubberduck.
Source Firkin
Background pattern 230 (colour 3) #2303
Green CC 0To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Beechwood #1295
Wood CC 0ZeroCC tileable beechwood wood texture, generated in Neo Texture Edit by me. CC0
Source Sojan Janso
Repeating Wood Straw Background #887
Wood CC BY-SA 3.0A repeating background with wood/straw like texture.
Source V. Hartikainen
Floral design 91 #1814
Dark CC 0From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
Clean gray paper #859
Paper CC BY-SA 3.0On a large canvas you can see it tiling, but used on smaller areas, it’s beautiful.
Source Paul Phönixweiß
Diagonal Waves #1006
Gray CC BY-SA 3.0It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
Vichy@2X #72
Light CC BY-SA 3.0This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
Background pattern 274 #2041
Dark CC 0Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Colorful Floral Background No Black@2X #482
Light CC 0Colorful Floral Background No Black
Source GDJ
Decorative divider 221 #2224
Dark CC 0Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Stitched Wool@2X #844
Light CC BY-SA 3.0I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
Brick Wall@2X #1147
Wall CC BY-SA 3.0One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
Classy Fabric #611
Dark CC BY-SA 3.0This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor
Tileable Wood@2X #656
Wood CC BY-SA 3.0Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Xv@2X #315
Paper CC BY-SA 3.0Floral patterns will never go out of style, so enjoy this one.
Source Lasma
Prismatic Abstract Geometric Background #269
Noise CC 0Prismatic Abstract Geometric Background derived from an image on Pixabay.
Source GDJ
Green Fibers #91
Dark CC BY-SA 3.0The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Elegant Grid@2X #317
Wall CC BY-SA 3.0This is a hot one. Small, sharp and unique.
Source GraphicsWall