If you mean what the cakes are set on like what sweet dreams said if you dont have mdf or dont want to go buy it, a couple thick layers of cardboard also works and then wrapped in wrapping paper and cellophane.  Or a nice flat serving dish or even the plates that you can find for next to nothing what are meant to be used for candles.

I usually use the cake drums you can buy in the online shop on this website or thick cardboard. You can cover them in wrapping paper (make sure you cover the wrapping paper in cellophane, or you'll get moisture spots in the paper) or you can cover a cake drum in gumpaste, fondant or marzipan and decorate it to match your cake. A nice silver plate or mdf are other possibilities.

OMG   U r sooooooooooo helpful
really thanks alot 2 all of u

exactly ,my Q was about the base under the cake,it's really a good idea 2 use 2layers of cartoons.

please 1 more Q
where can i buy the mdf?where can i buy the cheepest?????

Het spijt me mijn nederlands is niet perfect,daarom schrijf ik in het engels.;)

ya Canadesje maybe i have 2 write in dutch 2 practice it,but then i'll make alot of mistakes hhhhhh

I think you mean Karwei instead of Kwantrum. 

Thanks Very Much....