Soldering terminology

Fluxing agents, such as R and RMA fluxes, that have rosin (Aleppo pine resin) as the main ingredient as well as activators. Lately, the solids content, i.e. the percentage of solid rosin is frequently seen as problematic because a high proportion of solids makes the cleaning after soldering more difficult. Correspondingly, fluxing agents with minimum solids content are in demand.