This tutorial explains how to replace raised details with scribed lines. Prior to about twenty-five years ago, the typical plastic model airplane kit had unrealistic-looking raised panel lines or countless rows of rivet heads covering the model’s surface. This is because it was too expensive to develop the steel injection molding tools that could simulate recessed panel lines. During the late 1980’s we started to see models with more realistic-looking recessed panel lines. This was due to advances in the mold-cutting techniques that made it made it possible to economically develop steel molds with the raised details necessary to create the recessed features in the injection molded plastic parts. However, many kits made from older injection molds are still on the market today and some newer kits have some raised features that would look much more realistic when converted to recessed features.
There are many reasons to convert to recessed panel lines and details. A big advantage of recessed features is that they can receive a light wash to show weathering as part of the finishing coats. Also, kits rarely assemble so that opposing parts align perfectly. Panel lines often have to be removed and re-scribed. Lastly, a high gloss finish will highlight surface detail making recessed lines much more desirable.
There are a variety of scribing tools from which to choose. There is the traditional sickle-shaped scribing tool shown in the photo as well as almost any tool with a thin V-shaped point such as a sewing pin, number 11 Xacto blade or a needle in a pin vice. Along with choosing a scribing tool, you will need to choose a guide or template suitable for the project. For a flat surface requiring straight lines, you can use almost any straight surface. There are a number of scribing templates produced by aftermarket modeling companies. For tightly curved surfaces such as the fuselage, you can use label making tape like that made by Dymo. It will contour to the surface while being thick enough to act as a guide to your scribing tool.
Usually the first step when scribing a plastic airplane model is to make smooth the parts to be scribed. You can start by shaving off as much detail as possible with a dull hobby knife (a sharp blade increases the chance of gauging into the surface). After shaving, finish the removal by lightly wet sanding with fine sandpaper (800-grit or finer). After sanding and shaving, it is often possible to still see the faint remnants of the original panel lines making then useful as a guide to scribe the recessed details.
Make sure that your parts do not move while scribing. Secure them with tape onto a cutting pad and support contoured parts so that they are not depressed during scribing. How deeply to scribe is a matter of preference and experience. Do you want the scribed surface details to dominate the finished model or do you want them to be a subtle detail?
You will notice that scribing plastic creates a ridged groove. To achieve the illusion of clean, fully recessed panel lines, these ridges need to be removed. Ridges can be removed by more wet sanding. Sanding will tend to fill the scribed lines with wet dust. This can be removed by scrubbing in soap and water.