Scribing is the process of cutting new panel lines into the surface of a model kit. Unlike panel lining, which fills existing grooves with color, scribing creates grooves that were not there before. It is how builders add custom detail, break up large flat surfaces, and make a kit look more complex and mechanical than the original design intended. Scribing is an intermediate technique that rewards patience and planning, and it is one of the most satisfying skills to develop because the results are permanent and highly visible.
This guide walks you through the tools, techniques, and common pitfalls so you can add your first custom panel lines with confidence.
What Is Scribing
Scribing uses a sharp, pointed tool to carve a thin groove into plastic. The groove mimics the recessed panel lines that Bandai molds into every kit, but you control where they go and how they look. Once scribed and panel lined, the new detail blends with the original molded lines, making the kit look like it came out of the box with more surface complexity. The technique works on all plastic Gunpla kits regardless of grade or scale.
Why Add New Panel Lines
Factory-molded panel lines follow a standard pattern that prioritizes engineering constraints over visual detail. Large armor panels on HG kits often have only one or two lines across a flat surface that would, on a real machine, be covered in hatches, vents, and maintenance access panels. Scribing lets you add that detail yourself.
Scribing also helps with custom builds. If you are kit-bashing (combining parts from different kits), the original panel lines may not align. Scribing new lines across the joint hides the seam and makes the modified section look intentional rather than improvised.
Tools You Need
The core scribing toolkit is small and affordable:
- Scribing tool — either a dedicated panel line scriber (like the BMC chisel set or a Tamiya scriber) or a needle in a pin vise. Dedicated scribers have a flat chisel tip that cuts clean, consistent grooves. A needle works but produces a more ragged line that requires more cleanup.
- Dymo tape or Tamiya hard-edge tape — a thick, rigid tape that acts as a straight-edge guide. Regular masking tape is too flexible and shifts under pressure.
- Pencil — for marking line placement before committing to a cut.
- Sanding sticks — for cleaning burrs after scribing.
- Ruler or template — for measuring consistent spacing between lines.
All of these are available in our hobby tools collection. If you are building your first toolkit, see the best tools buying guide for recommendations.
Planning Your Lines
Never scribe freehand without planning. Study reference images of the mobile suit in anime, artbooks, or other builders' work. Look at how real military hardware uses panel lines: armor plates have rectangular seams, hatches have thin borders, and maintenance panels sit in logical locations near joints and vents.
Draw your planned lines on the plastic with a mechanical pencil. Pencil marks wipe off cleanly and let you evaluate the design before making permanent cuts. Step back and look at the overall pattern. Too many lines make a kit look busy. Too few make the scribed area look out of place against the stock detail. Match the density of the surrounding molded lines and your additions will look natural.
Taping Your Guide Lines
Straight scribing depends entirely on your guide. Lay a strip of Dymo tape (or hard-edge scribing tape) along the pencil line, pressing it firmly so it does not shift. The tape edge becomes your ruler. Your scribing tool rides against it, producing a line that is as straight as the tape itself. Without a guide, even experienced scribers produce wobbly lines that undermine the entire effect.
For curved lines, use thinner tape or flexible scribing templates. Curved scribing is significantly harder than straight and should be attempted only after you are comfortable with straight cuts. When in doubt, design your panel pattern using only straight lines: they are easier to execute and look cleaner on angular mecha armor.
Making the First Pass
Hold the scribing tool at a low angle against the tape edge. Apply light pressure and draw the tool toward you in a single smooth stroke. The goal on the first pass is to create a shallow guide groove, not a deep line. If you press too hard, the tool can skip off the tape edge and gouge the surface. Light, consistent pressure keeps the line under control.
After the first pass, you should see a faint scratch that follows the tape perfectly. This scratch will guide all subsequent passes and prevent the tool from wandering. Never skip this light first pass: it is the foundation of a clean line.
Deepening the Line
Run the tool along the same groove with slightly more pressure. Each pass deepens the line incrementally. Five to eight passes typically produce a groove that matches the depth of Bandai's factory-molded panel lines. The gradual approach gives you full control: you can stop at any point when the depth looks right, and you avoid the catastrophic slip that comes from pressing hard on the second pass.
Check the depth against the existing panel lines on the kit. Consistency matters more than depth. A shallow line that matches the surrounding detail looks better than a deep one that stands out as obviously added after the fact.
Cleaning Up
Scribing raises tiny ridges of displaced plastic along both sides of the groove, called burrs. Remove them by running a sanding stick lightly across the surface perpendicular to the line. Do not sand along the line, which can widen or fill the groove. A few passes with 600 to 800 grit sandpaper cleans the burrs without affecting the surrounding surface.
If you made a mistake, shallow scratches can be filled with thin CA glue or putty, sanded flat, and re-scribed. Deep mistakes may require filling with modeling putty and more extensive sanding. This is why the light-pass-first technique matters: catching a misaligned line on the first pass costs seconds to fix, while catching it on the eighth pass costs an hour.
Common Scribing Mistakes
Pressing Too Hard Too Soon
The tool slips, gouges the surface, and the damage is difficult to fix. Always start with light pressure. Your patience on the first three passes determines the quality of the finished line.
Using Flexible Tape
Regular masking tape bends under tool pressure and produces wavy lines. Invest in Dymo tape or dedicated scribing tape. The rigid backing resists deflection and keeps the tool tracking straight.
Scribing Across Thin Plastic
Some armor panels, especially on HG kits, are surprisingly thin. Scribing too deep can break through the plastic entirely. Before scribing any area, check the part thickness from the inside. If it is less than 1 mm, use shallower passes and stop early.
Ignoring Scale
A panel line that looks proportional on a 1/100 MG kit will look oversized on a 1/144 HG. Adjust your line width and spacing to match the scale of the kit. On smaller scales, use a finer chisel and tighter spacing.
When to Start Scribing
Scribing is not a beginner technique, but it is not expert-only either. If you have built five to ten kits and feel comfortable with panel lining, nub removal, and basic finishing, you have the hand skills to start scribing. Practice on spare runners or a cheap HG kit before committing to a kit you care about. The muscle memory develops quickly, and after two or three practice panels, you will feel the tool tracking cleanly and the grooves forming consistently. From there, every build becomes a canvas for custom detail.