300 and 330 gsm are basis weights, not a compatibility list
Basis weight is grams per square metre: a mass per area. Between two references, 300 and 330 gsm give a point of comparison, but they do not tell you whether the sheet will feed through your printer. What decides that is the route the paper takes through your printer, the thickness of the medium and your model’s limits.
Also compare the stated thickness
The catalogue lists the thickness announced by the supplier: 350 µm for 300 gsm matte and for 300 gsm Luster, 370 to 375 µm for 330 gsm matte and for 330 gsm holographic front / matte back. These figures describe the references on offer. They are not ProxyCardStock laboratory measurements, and not a threshold every printer accepts.
Deciding in four steps
- In your printer manual, find the accepted media type, thickness or basis weight, and the intended tray.
- Compare that information with the listing for the reference that interests you.
- Print a single test sheet before preparing a run.
- If feeding or printing is not satisfactory, stop the test and adjust the medium choice or settings.
Sources and scope
- ISO 536:2019, Paper and board: determination of grammage
The ISO standard identifies basis weight as a measurement specific to paper and board; it does not determine whether a medium is compatible with a given printer.
- ProxyCardStock catalogue
The 300 gsm, 330 gsm and thickness figures mentioned here come from the supplier. They are not measurements made by ProxyCardStock.