Thanks Hans for the answer. I made another try with file1.tex: \setuppapersize[A3,landscape][A3,landscape] \starttext \dorecurse{1500}{\input tufte \par \input knuth \par} \stoptext and merge.tex: \definepapersize[A3large][width=320mm,height=450mm,offset=0pt] \setuppapersize[A3,landscape][A3,landscape] \setuplayout [backspace=0pt,marking=on, height=middle,width=middle,location=middle, topspace=0pt, header=0pt, footer=0pt] \starttext \insertpages[file1.pdf][width=0pt] \stoptext The results are: 799537 ago 7 17:55 file1.pdf 1515097 ago 7 17:56 merge.pdf Also pdffonts file1.pdf give name type emb sub uni object ID ------------------------------------ ------------ --- --- --- --------- EGNYTD+CMR12 Type 1 yes yes no 6 0 but pdffonts merge.pdf give name type emb sub uni object ID ------------------------------------ ------------ --- --- --- --------- AGPRLI+CMSS8 Type 1 yes yes no 15 0 MGUYCG+CMR12 Type 1 yes yes no 7 0 : : MGUYCG+CMR12 Type 1 yes yes no 7 0 ie the line MGUYCG+CMR12 Type 1 yes yes no 7 0 is repeated 408 (yes, four hundred) times . Do I mess with pdftex.cfg or some *.map files ? luigi