A Fullbright pack simply removes the "darkness overlay" from the game. Normally, light levels below 7 render blocks in shadow. A Fullbright pack forces the game to render every block as if it were in direct sunlight (Light level 15).
💡 Quick Tip: Most dedicated Fullbright packs for 1.12.2 require OptiFine to successfully manipulate the game's lightmap and turn dark pixels completely clear. ⚠️ Server Rules Warning minecraft 1122 fullbright texture pack updated
: Runs on almost any hardware without performance hits. A Fullbright pack simply removes the "darkness overlay"