A clean panel line can make an Entry Grade look more intentional and give an MG or RG the mechanical separation it deserves. Learning how to panel line Gunpla is less about using the darkest possible ink and more about matching the material, tool, and cleanup method to the kit in front of you.
Panel lining is one of the highest-impact upgrades available to a straight build. It defines armor breaks, vents, hatches, and molded surface detail that can disappear under normal room lighting. It can also go wrong quickly: excess wash can stain bare plastic, strong solvents can damage certain parts, and heavy black lines can make a 1/144 kit look more like a cartoon than a machine.
Choose the Right Panel Line Tool for Your Gunpla
Your kit's plastic, its grade, and whether you plan to paint it should decide the tool. There is no single best panel liner for every HG, RG, MG, or PG build.
For a first HG or Entry Grade, a fine-tip Gundam Marker is the most controlled option. Trace the recessed line lightly, then wipe away minor overrun with a cotton swab or soft cloth. Fine-tip markers are especially useful on shallow, short lines where a liquid wash may not flow consistently. They are also a sensible choice for builders who want to detail a kit without adding a clear coat step.
Pour-type panel line markers are faster on long, connected grooves. Touch the nib to one point in a recessed line and capillary action carries the ink along the channel. The finish can look excellent on PS plastic, but use restraint around ABS parts and assembled joints. Apply the ink sparingly, do not flood a seam, and test the method on a leftover runner first.
Enamel panel line washes, including bottle-style accent colors, give the sharpest and most scale-model-like results when used over a gloss clear coat. The thin wash runs beautifully through engraved detail, particularly on MG armor, Ver. Ka surfaces, and large 1/100 parts. The trade-off is solvent exposure. Enamel thinner can make unprotected plastic brittle, especially ABS. A gloss barrier coat separates the wash from the plastic and makes cleanup much safer.
Water-based acrylic washes are generally gentler, though they do not always wick through fine channels as aggressively as enamel. They work well over paint and clear coats, and they are a good option when you prefer a lower-risk workflow. For very precise work, a fine brush and thinned acrylic paint can be more useful than a pre-mixed wash.
Match the Color to the Armor, Not Just the Line
Black is not automatically the right answer. On white armor, black gives a high-contrast anime finish that suits many modern Gundam designs. Gray is more restrained and often looks better on 1/144 kits, where every line is already visually compressed.
Use brown on red, yellow, orange, and warmer off-white armor. It creates definition without the harsh outline effect of black. Dark blue, navy, and purple sections usually benefit from gray or black depending on how dramatic you want the result. On dark gray, black, or deep blue armor, try dark gray, lighter gray, or even a subtle metallic tone instead of black, which may vanish entirely.
A useful rule is to build contrast by value, not habit. The panel line should be visible from normal viewing distance, but it should not compete with the kit's color separation, decals, or weapon details. An RG with layered armor can support stronger contrast than a simple SD kit. A weathered military-style build may also call for brown-gray lines rather than clean black ones.
How to Panel Line Gunpla Step by Step
Start before final assembly whenever possible. Individual armor parts are easier to hold, easier to clean, and less likely to trap excess ink around a joint. If you are working on a completed kit, remove armor pieces where practical rather than trying to flood panel lines beside a moving elbow, knee, or shoulder mechanism.
1. Clean and inspect the surface
Remove sanding dust, skin oils, and plastic shavings with a soft brush or clean cloth. Inspect the lines under a bright desk lamp. Some Bandai parts have crisp, deep channels ready for a wash, while others have shallow molded marks better suited to a fine-tip marker.
If a line is so shallow that it stops and starts, consider deepening it with a dedicated scriber before panel lining. This is optional, not a requirement. On a beginner build, it is better to panel line cleanly in the existing detail than to rush into rescribing every armor plate.
2. Apply ink in small sections
With a fine-tip marker, use short strokes rather than dragging the nib across an entire part. Let the recessed groove guide the tip. For pour-type markers or washes, touch the liquid to an intersection, corner, or deepest point of the channel and allow capillary action to do the work.
Do not keep adding ink because a line looks faint while it is still wet. Give it a moment to travel. If the line fails to flow, the channel may be too shallow, blocked by dust, or interrupted by an unclean nub mark.
3. Let the panel line set, then clean it up
Cleanup is what separates a crisp finish from a stained one. For marker ink, a cotton swab, soft eraser, or lightly dampened swab can remove small mistakes, depending on the marker type and surface. Work across the line, not along it, so you do not pull pigment out of the recess.
For enamel washes over a gloss-coated or painted surface, use a small amount of enamel thinner on a cotton swab, makeup sponge, or pointed cleanup brush. The tool should be barely damp, never dripping. Gently wipe the raised surface and leave the pigment inside the engraved line. Too much thinner can strip paint, soften a clear coat, or carry wash into unwanted areas.
If you are panel lining bare plastic, avoid using enamel thinner as a general cleanup solvent. A marker-based workflow is the safer route unless you understand the plastic type and have tested your products first.
4. Check the part under normal display light
A panel line that looks perfect under a bright lamp can be too strong on a shelf. Set the part down, step back, and view it under the light where the kit will actually be displayed. If the contrast is too heavy, soften the line with careful cleanup or switch to a lighter color on the remaining armor.
This quick check matters most on white HG and RG kits. Their smaller surfaces can become visually busy fast, especially after adding decals and top coat.
Protect Your Work With the Right Clear Coat
If the kit is painted, panel line over a gloss clear coat. Gloss gives washes a smooth surface to flow across and makes excess pigment easier to remove. After the panel lines and decals are fully dry, a final top coat sets the finish: flat for a matte military or anime display look, satin for a restrained factory finish, or gloss for a polished custom build.
For an unpainted straight build, a final top coat can still unify the plastic, panel lines, and decals. Matte top coat slightly reduces the toy-like shine common on bare runners, but it can also mute metallic stickers and clear parts. Mask or remove those pieces if their finish matters to the project.
Keep clear coats light. Several mist coats are safer than one wet coat, particularly around panel-lined details where heavy spray can cause ink to bleed or react.
Common Panel Lining Mistakes and Practical Fixes
The most common mistake is using too much liquid. A recessed line only needs enough ink to start the flow. If the wash pools around a vent, seam, or peg hole, wick it away immediately with the corner of a paper towel or a clean brush.
Another frequent issue is panel lining every molded division on the kit. Some lines represent actual armor separations; others are small decorative marks or undercuts that do not need full contrast. On a clean RX-78-2-style build, selective lining often looks more convincing than outlining every surface.
Be cautious with assembled RG inner frames, ABS joints, and tight mechanical areas. Do not let pour-type ink or enamel wash collect near stress points. If you notice whitening, cracking, or a part becoming unusually stiff, stop using that product on the affected material and move to a safer marker or acrylic method.
Finally, do not judge your first attempt too harshly. Panel lining is a cleanup skill as much as an application skill. A few spare armor parts, leftover runners, and a simple EG or HG kit provide better practice than testing a new wash for the first time on an expensive MGEX or limited release.
The best panel lines do not announce the tool used to make them. They simply make the armor read more clearly, whether the kit is a quick 1/144 weekend build or the centerpiece of a carefully finished 1/100 display.
