Installing a resource pack in Minecraft 1.12 is a straightforward process that does not require a mod loader like Forge, though you may use OptiFine for better performance.
Some popular X-ray resource packs for Minecraft 1.12 include: minecraft 1.12 xray resource pack
: Specifically optimized for 1.12.2, this pack is ideal for players on lower-end systems who need performance while mining. Key Features for 1.12.2 Gameplay How To Get XRay in Minecraft Java 1.21.11 Installing a resource pack in Minecraft 1
: While optional, OptiFine is highly recommended to gain a "night vision" effect, which is necessary to see ores deep underground without torches. minecraft 1.12 xray resource pack