How to Panel Line a Model Kit: Tools and Clean Techniques

Quick answer

Panel lining is easiest when you match the tool to the surface: use a fine-tip panel line marker for quick, controlled lines on bare plastic, or a panel wash for recessed details and a weathered look. Whichever you choose, work on a clean, dry surface, let the line cure fully, and clean up immediately with a mild solvent on a swab. If you want a low-risk start, a gray or brown fine-tip marker on a light-colored kit gives clean results with almost no cleanup.

Match the tool to the surface and your goal

The biggest decision is marker versus wash, and it comes down to control and finish. A fine-tip panel line marker lays down a thin, opaque line exactly where the nib touches, so it suits crisp edges, small vents, and beginners who want predictable results. A panel wash flows into recesses by capillary action, so it excels on deep panel lines and textured surfaces where a marker would skip or pool. If you want a clean, anime-style look, start with a marker. If you want a mechanical, slightly weathered look, a wash is the better fit. You can also combine them: wash the deep recesses, then marker the shallow surface lines.

Prepare the surface before any line goes down

Panel lining amplifies whatever is underneath, so remove dust, mold release, and sanding residue first. A quick wipe with a dry microfiber cloth or a soft brush is enough for most kits. If you sanded parts, rinse or brush away the plastic dust, because it will mix with the line and turn it muddy. Work in a well-lit area with a neutral background so you can actually see the panel line you are tracing. For a kit with a special finish, such as the Bandai Gundam Base Limited RG 1/144 Hi-Nu GUNDAM Titanium Finish, the coated surface is less absorbent than bare plastic, so test your chosen method on a hidden area first. That titanium finish is a premium look, and aggressive solvent or repeated rubbing can dull it, so go lighter than you would on a standard kit.

Choose a color that reads as a shadow, not a stripe

Panel lines are shadows, so the color should be a darker version of the surrounding plastic, not pure black on everything. Gray works on white and light gray armor, brown suits reds, yellows, and warm tones, and black is best reserved for dark blue, dark gray, or black parts where you need contrast. On a white kit, a black line can look like a drawn stripe; a gray line looks like a natural seam. If you are unsure, buy one gray and one brown marker and test on the runner before committing to the whole kit.

Control the line: short strokes, light pressure, and a clean nib

With a marker, draw in short overlapping strokes rather than one long drag, and let the nib do the work with light pressure. Heavy pressure flattens the tip, widens the line, and can gouge soft plastic. If the line looks too thick, you are pressing too hard or the nib is worn. With a wash, touch the brush to one end of the recess and let capillary action pull it along; do not scrub it in. If the wash beads up, the surface may still have mold release or oil from your fingers, so clean it and try again. Keep a dry swab handy to catch drips before they dry.

Clean up at the right moment

For markers, cleanup is usually unnecessary if you stayed inside the line, but you can remove slips with a swab lightly dampened with isopropyl alcohol. For washes, wait until the wash is touch-dry but not fully cured, then wipe the raised surface with a swab barely dampened with the appropriate thinner. If you wait too long, the wash stains the surrounding plastic and you will need to sand or repaint. If you wipe too early, you will pull the wash out of the recess. The window is short, so work in small sections rather than washing the entire kit at once.

Seal the lines so they survive handling

Panel lines sit on the surface and will wear away with handling, dusting, and posing. A clear topcoat locks them in and evens out the sheen. Use a matte coat for a military or realistic look, or a gloss coat if you want a clean, shiny finish. Apply thin, misting coats rather than one wet coat, because a heavy coat can reactivate markers and washes. If you used a wash, let it cure for at least several hours, preferably overnight, before topcoating.

Panel lining step by step

1. Clean the parts and test your tools: Wipe dust and sanding residue from the plastic, then test your marker or wash on a hidden runner or the back of a part. On a coated kit like the Hi-Nu Titanium Finish, this test tells you whether the surface accepts the line or repels it. Checkpoint: the test line should be even and should not bead up or dull the plastic.
2. Line the recesses with the right tool: Use a fine-tip marker for shallow surface lines and a wash for deep recesses. Draw in short, light strokes with the marker, or touch the wash to one end of a recess and let capillary action pull it through. Common mistake: pressing hard with a marker flattens the nib and widens the line.
3. Clean up before the line cures: For marker slips, wipe with a swab lightly dampened with isopropyl alcohol. For wash, wait until touch-dry, then wipe the raised surface with a swab barely dampened with thinner. Work in small sections. Checkpoint: the recess stays dark and the raised surface is clean, with no staining around the line.
4. Let everything cure, then topcoat: Allow markers and washes to cure fully, ideally overnight, before applying a thin mist coat of matte or gloss clear. Build the coat in light passes rather than one wet pass. Common mistake: topcoating too soon reactivates the line and smears it across the part.

Products that suit panel lining practice

• Bandai Gundam Base Limited RG 1/144 Hi-Nu GUNDAM Titanium Finish: Bandai Gundam Base Limited RG 1/144 Hi-Nu GUNDAM Titanium Finish is a Real Grade kit from the Universal Century line with a titanium finish coating on the plastic parts, and it is a special order that requires 6-8 weeks. The coated surface is less forgiving than bare plastic, so test your marker or wash on a hidden runner first and avoid harsh solvents that can dull the finish. Because it is a special order, plan your build and panel lining supplies before the kit arrives.
• Motor Nuclear MNP-XH13 Wei Yuan Shi (Heavy Firepower Type) Metal Frame Model Kit: Motor Nuclear MNP-XH13 Wei Yuan Shi (Heavy Firepower Type) Metal Frame Model Kit reimagines the core Wei Yuan frame as a specialized siege and suppression unit with a massive array of long-range weaponry and an asymmetrical silhouette, built with the series' signature internal frame. A kit with this much weaponry and an internal frame has many small recesses and mechanical details, which is exactly where a panel wash shines. The asymmetrical shape also means you should line one side at a time and check your work from multiple angles.