Panel lining is flowing a dark wash or fine marker line into the recessed grooves molded across a kit’s surface, so the “panels” read as separate plates with depth and shadow. It is the highest-impact twenty minutes in the hobby — a snap-built kit with crisp lining looks finished.
The two beginner routes: a panel-line accent color (touch the groove, capillary action draws the line, wipe the excess) or a fine-tip lining marker for a no-solvent approach. Either way, work over a gloss or bare-smooth surface and seal with a topcoat after.
Go deeper in our panel lining & decals guides.