is it true you can't print heavier than 300gsm paper on a normal commercial digital printer, and that for heavier stuff you have to go litho?
300 gsm is the standard upper limit right now for color copiers / light production printers. The igen4 is speced for up to 350 gsm. The exception is the small xante illumina that is speced up to 502 gsm, but the print quality is slightly "bold" and not quite as natural as some other printers and the cost per print is relatively high for a run of any length, but if you need really heavy stock, it's the one machine built for it.