The Void Cube mod adds four decorative blocks that feature the end portal shader so that you can build your own void
There are two blocks, each with two variants. The regular variant's center ingredient is a blaze powder. The alt variant's center ingredient is an Eye of Ender.
The bordered versions are crafted by surrounding the ingredient with any colour of stained glass.\
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The borderless versions are crafted by surrounding the ingredient with regular glass.\

Credits
Ageuxo - Coding\ oude_henky - Idea and border texture
How to Install Void Cubes (Mod)
Void Cubes by ageuxo is verified for Fabric, Forge, Quilt across Minecraft versions 1.19.2, 1.20.1 (latest release: 1.3.0, file size: 32 KB). Follow the steps below to install it safely from ModCraft.tv:
- Click the Download button above and select your Minecraft version (1.19.2, 1.20.1) and platform (Fabric, Forge, Quilt).
- Make sure you have the compatible loader or environment installed for Fabric, Forge, Quilt.
- Move the downloaded Void Cubes file into your Minecraft
.minecraft/modsfolder and launch the game.