I am experimenting with creating a multi layered book item with decoration layers as separate textures. After working out some item properties, I am able to render an item with multiple textures but get artifacts on the sides, as shown on the image.

The textured are loaded using item properties:
 

		@SubscribeEvent
		public static void onFMLCommonSetupEvent(FMLCommonSetupEvent event) {
			event.enqueueWork(() -> {
				BookItem item = Items.BOOK_ITEM.get();
				ItemProperties.register(item, BookItem.LEVEL, (stack, l, e, s) -> BookItem.getLevel(stack));
			});
		}

I've had a look at how the spawn egg textures work as it does closely what i want and the split the egg and spot textures into two and match exactly into each other as opposed to overlap textures on top of another.

I've also experimented with custom models and hoped that tinkering with different RenderTypes would do the trick (e.i. using RenderType#solidEntity, which fixes my problem for entities but not on items ), but to no avail.

I could edit my textures to fix this issue but I want to keep it more dynamic was wondering whether there was another way to overcome this issue?

An uneducated guess: can you move the layers by a 1000th in any direction? It works on custom models via Blockbench.