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.
Bandai Gundam, Paint, Model Trains
Vintage Revell HOT ROD' Custom 57 Chevy Nomad Model Car Kit
Gundam Planet - GM501 Gloss Clear Gundam Marker
This is the GM01 Black Fine Line Gundam Marker from Bandai.
Bandai Gundam Marker Black Fine Line
Gundam Planet - GMS125 Gundam Marker Metallic Set 2 (Set of 6)
Gundam Marker Black (Fine)
Gundam Marker Pour Type for Panel Lines Set, GUNPLA SA
gundam marker Kusakusa Gunpla
Panel Lining for Gunpla 101 - Gunpla 101
Panel Lining for Gunpla 101 - Gunpla 101
Mr. Hobby Gundam Markers – Clarksville Hobby Depot LLC
The metallic markers are so worth it! : r/Gunpla
Mr. Hobby Gundam Marker GM01 Black (Fine Tip For Panel Lines) - A-Z Toy Hobby