artwork will be rounder down because the database is in mils with precision 3requiring artwork precision of 7decimal places,which is greter than the maximum of 6.rounding down might result in inaccuate arc coordinates in the output files and possible shape/viod ploting failures. for raster artwork formats, artwork accuracy must be at least one place greater than the database accuracy,up to the maximum accuracy allowed by the selected output format ,use GDII or IPC2581 manufacturing format that support the level of database accuracy set.