Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Colorful Floral Background 3 No Black
Source GDJ
The classic notebook paper with horizontal stripes.
Source Are Sundnes
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!
Source Dertig Media
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Can never have too many knitting patterns, especially as nice as this.
Source Victoria Spahn
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless pattern formed from miutopia's cakes on a tablecloth.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
One more sharp little tile for you. Subtle circles this time.
Source Blunia
Zero CC tileable seed texture, edited by me to be seamless from a Pixabay image. CC0
Source Sojan Janso
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ
Not the most creative name, but it’s a good all-purpose light background.
Source Dmitry
This was formed by distorting an image of a background on Pixabay.
Source Firkin