How I did the Gundam GP01 Zephyranthes panel lines

1/144 RG RX-78GP01 Gundam GP01 Zephyranthes

1/144 RG RX-78GP01 Gundam GP01 Zephyranthes

Here's how I did the panel lines
Simply draw lines with marker the thickness of the marker does not matter
After you erase the excess, using a cotton swab dipped in alcohol or I used a blender which is the same