3D Systems was founded in Valencia, California by Chuck Hull, the inventor and patent-holder of the first stereolithography (SLA) rapid prototyping system. Prior to Hull's introduction of SLA rapid prototyping, concept models required extensive time and money to produce. The innovation of SLA reduced these resource expenditures while increasing the quality and accuracy of the resulting model. Early SLA systems were complex and costly, however, and required extensive redesign before achieving commercial viability. Primary issues concerned hydrodynamic and chemical complications. In 1996 the introduction of solid-state lasers permitted Hull and his team to reformulate their materials. Engineers in transportation, healthcare and consumer products helped fuel early phases of 3D Systems' rapid prototyping research and development. These industries remain key followers of 3D Systems' technology.