▁liquid ▁res in ▁surface ▁and ▁light ▁is ▁project ed ▁onto ▁the ▁res in ▁to ▁c ure ▁it ▁in ▁the ▁shape ▁of ▁the ▁layer . ▁The ▁technique ▁has ▁been ▁used ▁to ▁create ▁objects ▁composed ▁of ▁multiple ▁materials ▁that ▁c ure ▁at ▁different ▁rates . ▁In ▁research ▁systems , ▁the ▁light ▁is ▁project ed ▁from ▁below , ▁allowing ▁the ▁res in ▁to ▁be ▁quickly ▁spread ▁into ▁uniform ▁thin ▁layers , ▁reducing ▁production ▁time ▁from ▁hours ▁to ▁minutes . ▁Com mer cially ▁available ▁devices ▁such ▁as ▁Ob jet ▁Con nex ▁apply ▁the ▁res in ▁via ▁small ▁no zz les . ▁ ▁Cont inu ous ▁liquid ▁interface ▁production ▁( CLI P ) ▁is ▁another ▁form ▁of ▁add itive ▁manufact uring ▁that ▁uses ▁the ▁D LP ▁based ▁photo ▁polym er ization ▁process ▁to ▁create ▁smooth - s ided ▁solid ▁objects ▁of ▁a ▁wide ▁variety ▁of ▁shapes . ▁ ▁The ▁continuous ▁process ▁of ▁CLI P ▁begins ▁with ▁a ▁pool ▁of ▁liquid ▁phot opol ym er ▁res in . ▁Part ▁of ▁the ▁pool ▁bottom ▁is ▁transparent ▁to ▁ult rav io let ▁light ▁( the ▁" window "). ▁Like ▁D LP ▁systems ▁before ▁it , ▁ult rav io let ▁light ▁beam ▁sh ines ▁through ▁the ▁window , ▁ill umin ating ▁the ▁precise ▁cross - section ▁of ▁the ▁object . ▁The ▁light ▁causes ▁the ▁res in ▁to ▁solid ify . ▁The ▁object ▁r ises ▁slowly ▁enough ▁to ▁allow ▁res in ▁to ▁flow ▁under ▁and ▁maintain ▁contact ▁with ▁the ▁bottom ▁of ▁the ▁object . ▁CLI P ▁is ▁different ▁from ▁traditional ▁D LP ▁processes