This is the first Technical Preview for Simplified Textures 1.20.0 (Horizon Update) and will add more textures.

•Blaze Rod is simplified.
•Blaze Powder is simplified.
•Bowl is simplified.
•Chalkboards (all variants) is simplified.
•Empty Map is simplified.
•Filled Map is simplified.
•Locked Map is simplified.
•Nautilus Shell is simplified.
•Nether Star is simplified.
•Nether Wart is simplified.
•Painting item texture is simplified.
•Paper is simplified.
•String is simplified.
•Turtle Shell is simplified.
•Totem of Undying is simplified.
•Scute is simplified.
•Diamond Helmet, Diamond Chestplate, Diamond Leggings, and Diamond Boots is simplified.
•Apple, Golden Apple, and Enchanted Golden Apple is simplified.
•Beetroot is now simplified.
•Popped Chorus Fruit and Chorus Fruit is simplified.
•Cookie is simplified.
•Diamond Horse Armor is simplified.
•Acacia Door, Birch Door, Dark Oak Door, Iron Door, Jungle Door, Spruce Door. and Oak Door (item texture) are simplified.
•Dried Kelp is simplified.
•Dyes are now simplified.
•Ink Sac is simplified.
•Cocoa Beans is simplified.
•Bone Meal is simplified.
•Eye of Ender is simplified.
•Ender Pearl is simplified.
•Bottle of Experience (Experience Bottle) is simplified.
•Feather is simplified.
•Flint and Steel is simplified.
•Flint is simplified.
•Ghast Tear is simplified.
•Gunpowder is simplified.
•Heart of the Sea is simplified.
•Hopper (item texture) is simplified.
•Lantern (item texture) is simplified.
•Sweet Berries is simplified.
•Amethyst Block is simplified.
•Budding Amethyst is simplified.
•Oak Logs, Birch Log, Spruce Log, Jungle Log, Acacia Log, Dark Oak Log, and their respective wood variants is removed temporarily.