The pixel look is unusually kind to a home printer, because the whole aesthetic is squares of flat colour with hard edges — exactly what cheap printers do well.
A pixel banner. One letter per sheet, chunky blocks, black outline. Hung high, it sets the whole room.
Square confetti. Sheets of coloured squares, cut with a guillotine or scissors, scattered on the table. Nothing says pixel faster and nothing is cheaper.
Black-outlined signs. "High score", "Level up", "Player one" on the door, the drinks, the cake table. Chunky font, thick outline, nothing else.
Gradients, soft shadows and photo-realistic anything. They fight the look and they eat ink. The whole style is flat colour and hard edges; fighting that just produces an expensive smudge.
Flat blocks of solid colour are the most ink-hungry thing a home printer does. Outline-only versions for the children to colour themselves cost almost nothing, look better on a wall, and turn the decorating into the first activity of the party.
Bright primaries and a hard black outline. Red, blue, yellow, green, white, and black. Muted or pastel palettes read as something else entirely.
Yes, and it works well — outline-only pixel art is a legitimate look, and it becomes a colouring activity rather than just decoration.
No. Ordinary paper is fine for banners and signs. Card only matters for anything that has to stand up.
Part of our guide to Retro arcade party.