{HEAD ~ The apparatus}, which may have a configuration similar to that of {TAIL ~ a felt tip} marking pen, allows convenient use of low volatility solvents in the catalyst solution 
{ HEAD ~ The apparatus } , which may have a configuration similar to that of { TAIL ~ a felt tip } marking pen , allows convenient use of low volatility solvents in the catalyst solution
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH