A panel-lining marker can make molded armor details easier to see without painting the whole model. The useful first question is not which color to buy. It is which marker is suitable for the surface you want to mark.
For a small first experiment, choose a fine-tip liner specified for your unpainted plastic and test it on a matching spare piece. Pour-type markers suit recessed channels, but their flowing ink and surface restrictions deserve extra attention. A painting marker or weathering marker is a different tool, even when the barrel carries the same Gundam branding.
Identify the marker before choosing a method
Mr. Hobby’s Gundam Marker catalog separates GM01–03 liner markers, GM301–303 pour-type markers, and the Real Touch range. The liners draw directly; Real Touch is intended for dirt and shading effects. Those product families should not be treated as interchangeable panel-lining formulas.
Fine tip: useful when you want to trace a short recessed detail and control exactly where the point goes.
Pour type: useful when an approved surface has a connected recessed channel that the ink can travel through.
Painting marker: choose for an area of color, after checking that exact marker’s instructions.
Weathering marker: choose for the intended shading effect, rather than assuming it behaves like a technical liner.
Write the product code on a small test label. “Black Gundam pen” is too vague when you later want to reproduce a result or find the correct cleanup instructions.
Read the runner material and the surface history
Check the kit manual and the material markings on its runners. Different runners in the same box can use different plastics. Also ask whether the part has already been painted, clear-coated, or treated with another product. A bare spare runner is not a representative test for a painted armor panel.
For GM301P–303P, Mr. Hobby’s pour-type product guidance excludes painted or coated models. Do not turn a generic “gloss before panel lining” tip into permission to use these markers over a gloss coat. Follow the restrictions on your exact package, including plastic exclusions; do not use a solvent marker on ABS when its instructions prohibit it.
If the material is unclear, pause that part of the project. Taking a photo of the runner marking and checking the exact product directions is a better next step than trying an inconspicuous spot on an irreplaceable joint.
Choose contrast on a sample
Color is an aesthetic decision once compatibility is settled. Our suggested starting point is a restrained gray on pale armor, with a darker line only where you want stronger separation. Compare samples in the light where the model will be displayed. A line that looks dramatic under a work lamp may dominate a small face or chest on the shelf.
Try one repeated detail before committing to every groove. Leave the matching piece untouched and compare them at arm’s length. You do not have to outline every molded feature; a selective result can keep the original color separation readable.
A controlled first session
Choose one removable armor piece. Finish its nub cleanup first. Work before assembly where practical so you can see where liquid goes.
Prepare a representative test. Use the same approved plastic and surface preparation. Test both the mark and the planned cleanup.
Apply sparingly. With a liner, trace a short section. With an approved pour-type setup, touch a recess rather than flooding seams or hidden connections.
Follow the product’s drying and cleanup directions. Check the result after it has dried, not just while the line is wet.
Inspect before repeating. Look for staining, surface changes, or ink that has escaped into places you cannot clean. Stop if the test behaves unexpectedly.
Keep the model supported on the bench. Holding a tiny part tightly while repeatedly wiping it can add stress and makes it harder to see how much pressure you are applying.
Cleanup belongs to the exact formula
The Mr. Hobby catalog describes rubber-eraser cleanup for its liner type. That does not establish an all-purpose cleanup method for every marker. Likewise, owning an eraser marker does not mean its solvent is compatible with every plastic, paint, or clear coat.
Prepare the approved cleanup tool before starting. Use a small, controlled contact area and a fresh section of the swab or cloth when directed. If a mark persists, avoid escalating through household solvents. Check the instructions and reassess the test first; aggressive cleanup can create a larger cosmetic problem than the original stray line.
What to buy first
Start with one appropriate liner color and its documented cleanup supplies. You can decide whether you want additional colors after finishing a small section. An entire marker set is useful only if you understand what the included pens do.
Browse Artrovo Gundam’s current hobby supplies by exact product name and code. Real Touch markers may be useful for a later weathering project, but are not a substitute recommendation for a fine-tip liner. Availability and purchase options are shown on each listing.
If you are still assembling your first toolkit, the first-build tools guide helps separate essentials from optional finishing supplies. For a panel with a rough gate mark, finish the nub cleanup before adding ink.
