With a name this awesome, how can I go wrong?
Source Nikolay Boltachev
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Retro Circles Background 7 No Black
Source GDJ
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
Pass parameters to the URL or edit the source code variables to configure the graph paper for the division desired.
Source JayNick
Prismatic Snowflakes Pattern 2 No Background
Source GDJ
A bit of scratched up grayness. Always good.
Source Dmitry
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
A pattern derived from repeating unit cells each derived from part of a mosaic in paint.net. The starting point for the mosaic was a picture of some prawns!
Source Firkin
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay
This is the remix of "Strawberry Pattern Background" uploaded by "GDJ". Thanks. I realigned strawberries so as to get seamless and changed the BG color.
Source Yamachem
A free background pattern with abstract green tiles.
Source V. Hartikainen
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Has nothing to do with toast, but it’s nice and subtle.
Source Pippin Lee
From a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
Prismatic Groovy Concentric Background 5
Source GDJ