This neologism means the fact of reinforce a model structure when it’s big or includes heavy parts. All you have to do is fitting metalic rods (brass rods, most of the time) to ensure the structure sturdiness. This model parts are threaded into the rods, like a brochette. Ths major complication is to find a glue working with both metal and plastic (or resin). Bi-component epoxide glue works most of the time.