Panel lining is a simple but effective technique that can add depth and detail to your Gunpla model and make it look more realistic. By filling in the recessed lines, or "panels," on the model with a fine-tipped pen or brush and enamel or gundam marker, you can define the different parts of the model and make it stand
Fluorescent panel lining looks super good on the Nu Gundam Ver Ka. : r/ Gunpla
1st HG/panel lining/posing attempt all tips are welcome : r/Gunpla
How Hard is it to Build a Gundam Model?
SAB Panel Liner, Design CUSTOM PANEL LINES
HOW TO DESIGN AND MAKE CUSTOM PANEL LINES: Begginer Tips & Tricks
Anyone else panel line when its still on the runner? : r/Gunpla
How long does it take for you to panel line? : r/Gunpla
First time doing panel lining : r/Gunpla
This kit does require a lot of panel lining. Still trying to do them nicely. Any suggestions? : r/Gunpla