Figurise - The three easiest ways to improve your Gunpla straight
ANSAI Permeation Pen Panel Line Hobby Military Model
Use for inking to trace hollow lines. It g gives the model a three-dimensional feeling and makes it appear more realistic. The effect is stronger when you choose the color to ink according to the color of the model parts. In general, you can use black for dark parts, grey for lighter parts and brown for red parts.
Gundam Marker Gray (Fine) GM02
DuelMasterNG Gunpla: Tutorial - Panel Lining with Gold/Silver
How To Paint Everything: Gundam
This it the most popular panel liner. Available in 3 colors. GM01~03 Panel lining is the first step of Gunpla customization beginners can try. It is a
Gundam Marker ~ Ultra Thin Pen Point for Panel Lining 劃線筆,勾線筆 [油性]
How to do panel-lining
How to Make Your Gunpla Models Stand Out with Panel Lining – LA
Gunpla Panel Lining Tutorial – Gunbies
Gundam Marker Pour-Type Panel Liner (Select - Black, Brown, or
If you are new to Gunpla then I suggest you use this pen for panel