Emissive texture for item tutorial

I want to make an item (writable_book) have an partially emissive texture. I've seen it done with blocks, is it possible with items? Does anyone know of a good resource or tutorial that could help me figure it out? I'm new to doing anything fancy with texture packs and couldn't find much out there on how to do emissive textures.
I'm trying to do this in vanilla no mods/shaders.