For convenience we are placing papers, cards, and boards in different categories. We are calling thick papers cards, and very thick cards as boards.
Papers are most frequently described using grams per square metre (eg office paper is usually 80gsm). Wikipedia states that the paper~card boundary is 130gsm. We have sold 160gsm as card on ebay and had bad reviews along the lines "it's just thick paper". As is so often the case people have different understandings. We try to overcome this by saying, as we do on ebay, that 160gsm is "very thin card". 10gsm is too thin to support more than one or two photos if they, in turn, are printed on "thick card". We feel it is ideal for small albums, especially when the overall bulk has to be kept down. If in doubt then please do not "buy by post" - go to the high street where you can judge for yourself as to what is available.
Boards are described by thickness (eg a useful greyboard might be 2mm thick). More information on this is available at busybusy.co