▁ones ▁that ▁are ▁stack able . ▁There ▁are ▁also ▁some ▁forms ▁of ▁high l igh ters ▁that ▁have ▁a ▁w ax - like ▁quality ▁similar ▁to ▁an ▁oil ▁past el . ▁ ▁" D ry ▁high l igh ters " ▁( occ asion ally ▁called ▁" d ry ▁line ▁high l igh ters ") ▁have ▁an ▁applic ator ▁that ▁applies ▁a ▁thin ▁strip ▁of ▁high l ighter ▁t ape ▁( phys ically ▁similar ▁to ▁audio ▁t ape ) ▁instead ▁of ▁a ▁felt ▁tip . ▁Un like ▁standard ▁high l igh ters , ▁they ▁are ▁easily ▁er as able . ▁They ▁are ▁different ▁from ▁" d ry ▁mark ▁high l igh ters ", ▁which ▁are ▁sometimes ▁advert ised ▁as ▁being ▁useful ▁for ▁highlight ing ▁books ▁with ▁thin ▁pages . ▁ ▁" G el ▁high l igh ters " ▁contain ▁a ▁gel ▁stick ▁rather ▁than ▁a ▁felt ▁tip . ▁The ▁gel ▁does ▁not ▁ble ed ▁through ▁paper ▁or ▁become ▁d ried ▁out ▁in ▁the ▁pen ▁as ▁other ▁high l igh ters ' ▁in ks ▁may . ▁ ▁" L iqu id ▁High l igh ters " ▁in ▁a ▁range ▁of ▁colours ▁are ▁also ▁available , ▁and ▁because ▁they ▁put ▁more ▁in k ▁on ▁a ▁page ▁when ▁highlight ing , ▁make ▁words ▁stand ▁out ▁more ▁than ▁with ▁non - liqu id ▁types . ▁Also ▁the ▁fact ▁that ▁more ▁highlight ing ▁in k ▁is ▁put ▁on ▁the ▁page ▁with ▁liquid ▁high l igh ters ▁means ▁that ▁the ▁highlight ing ▁in k ▁is ▁much ▁more ▁resist ive ▁to