Ectoluminescence

or "Ectolum" for short

It's a mod that gives more purposes to a few of features already existing in vanilla minecraft, including: Glow Ink Sac, Phantom Membrane and Echo Shard.
Ideas for these features were taken, with the consent of the creator, from youtube video 'I Fixed "USELESS" Minecraft Features' by Nekoma (Note, that the mod only includes ideas for items listed above).

Features:

1. Using Glow Ink Sac on a Banner or Decorated Pot faces makes them emissive
2. Using Phantom Membrane on a Banner or any type of Sign causes its background to disappear
3. New items:
   • Clear Item Frame - A semi transparent Item Frame, that becomes invisible once you put an item inside. Perfect for creating displays with the Item visible, without the unnecessary texture of an Item Frame underneath! It's crafted from one Item Frame and one Glow Ink Sac.
   • Glow Torch - A waterloggable version of torch, that glows worse than Soul Torch on the surface, but also glows as bright as a torch when placed underwater. Crafted from Glow Ink Sac and a Stick.

Full preview of features listed above is available in the gallery :>

New trim effects:

Glowing

Makes the armor trim glow in the dark! There is little to none difference in daylight (also, due to lack of light in the UI, it's not really visible here. Check the gallery for better reference)

Echoing Effect: Fade

Makes the armor trim disappear periodically

Echoing Effect: Twinkle

Makes the armor trim periodically emissive (it is best observed in the dark)

Echoing Effect: Pigment

Combining an Echo Shard with a trimmed armor and any trim material makes the armor trim change color periodically, from the one from original trim, to a new one that depends on a material used

Info for commandblock users and developers

• All the blocks/mobs that you can use Glow Ink Sac on have optional ectolum.glowing (boolean) nbt that decides whether it's glowing or not
• Same with optional ectolum.hide_background (boolean) nbt for blocks that you can use Phantom Membrane on
• The only exception is Decorated Pot, which has optional ectolum.sherd_glow_overrides (byte array with 4 elements, eg. [B; 1b, 0b, 0b, 1b]) nbt deciding which faces in Sherds list glow
• Every trimable armor piece can have both: ectolum.glowing (boolean) and ectolum.hidden (boolean) nbt tags inside the Trim nbt compound, but also additional ectolum.echoing_layers (compound list) nbt containing information on how its properties changes between each "echo". Each "echoing layer" can have any of glowing (boolean), hidden (boolean) or material (trim material ID, eg. "minecraft:iron") specified, all of these parameters are optional. For example, in order to make a netherite trim with silence pattern glow for 3 intervals, and then not glow for another 3 (counting in the interval in which the default trim's parameters are read), so 6 intervals in total, the nbt would look like so: {Trim: {pattern: "silence", material: "netherite", ectolum.glowing: true ectolum.echoing_layers: [{}, {}, {glowing: false}, {}, {}]}}
• The Netherite Chestplate you can see on the icon, glowing with all the colors of the rainbow, you can currently only aquire in creative mode via commands. The command for it looks like so: /give @p netherite_chestplate{Trim:{pattern: "silence", material: "redstone", ectolum.glowing: true, ectolum.echoing_layers: [{material:"copper"},{material:"gold"},{material:"emerald"},{material:"diamond"},{material:"lapis"},{material:"amethyst"}]}}
• Openning a world without the mod will cause blocks and mobs loosing the nbt parts added by this mod, but the vanilla parts will remain intact. Ofc nbt tags in items will stay the same, so any echoing layers applied to armor's trim will be visible once the mod is added again

Shader used for screenshots in gallery: Photon