Paper 1@2X #16
 Paper  CC BY-SA 3.0

A slightly grainy paper pattern with small horizontal and vertical strokes.

Source Atle Mo

 More Textures
Prismatic Abstract Background Design No Black #404
 Noise  CC 0

Prismatic Abstract Background Design No Black

Source GDJ

Batthern #324
 Grid  CC BY-SA 3.0

Sometimes simple really is what you need, and this could fit you well.

Source Factorio.us Collective

Part of Bayeux Tapestry 3 #2448
 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

Patern dots #241
 Dark  CC 0

Pattern repeating background 48x48

Source Keistutis

Ravenna #354
 Wall  CC BY-SA 3.0

I guess this is inspired by the city of Ravenna in Italy and its stone walls.

Source Sentel

Diamond pattern (colour 2) #2284
 Green  CC 0

From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

Prismatic Arrows Background 2 #393
 Light  CC 0

Prismatic Arrows Background 2

Source GDJ

Background pattern 263 #2073
 Pink  CC 0

Actually remixed from a pattern on Pixabay. But then noticed a very similar one on Openclipart.org uploaded by btj51q2.

Source Firkin

Prismatic Groovy Concentric Background 2 #453
 Noise  CC 0

Prismatic Groovy Concentric Background 2

Source GDJ

Background pattern 225 (colour 5) #2323
 Blue  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