 Before the writing of " S.R. 819 " , the writers for The X @-@ Files felt that the character of Walter Skinner was becoming too " expendable " . John Shiban , the writer of the episode , decided to re @-@ work Skinner back into the series ' mythology by crafting the episode around him . Mitch Pileggi had to endure long bouts of make @-@ up application , a process that he admitted he " hated " . The nanobots in the blood sample were designed on a computer and then rendered for the final footage . 
 Before the writing of " S.R. 819 " , the writers for The X @-@ Files felt that the character of Walter Skinner was becoming too " expendable " . John Shiban , the writer of the episode , decided to re @-@ work Skinner back into the series <a href='null_genetive' title='1'><mark>'</mark></a>mythology by crafting the episode around him . Mitch Pileggi had to endure long bouts of make @-@ up application , a process <a href='null_relcl' title='2'><mark>that</mark></a>he admitted he " hated " . The nanobots in the blood sample <a href='uninflect' title='3'><mark>were</mark></a> designed on a computer and then rendered for the final footage . 
Before the writing of " S.R. 819 " , the writers fir da X @-@ Files felt dat the character of Walter Skinner was becoming too " expendable " . John Shiban , the writer of tdaepisode , decided to re @-@ work Skinner back into thdaeries  mythology by crafting thedaisode around em . Mitch Pileggi had to endure long bouts of make @-@ up application , a process he admitted he " hated " . The nanobots in the blood sample was designed on a computer and then rendered for the final footage .