Here's a breakdown:
* Fine to Medium Hair: 1 jar might be enough.
* Thick Hair: You'll definitely need 2 jars to ensure full and even coverage.
Factors that influence the amount:
* Hair Thickness: Thicker hair absorbs more dye.
* Porosity of Hair: More porous hair absorbs dye faster and may require more.
* Intended Coverage: If you are doing a full head application, you'll need more dye than if you're just doing highlights or an ombre.
* Color Intensity: Some colors need more dye for proper saturation.
* Personal Application Style: Some people are more generous with the dye application.
Recommendation:
If you're unsure, it's always best to buy 2 jars. It's better to have extra than to run out halfway through the dyeing process. You can always save the leftover dye for touch-ups later.