As member Zara pointed out, it is not the same plant as used for furniture. Natural rattan is the resin of the Garcinia hanburyi tree (mangosteen).
It is hard to find large chunks of rattan. You can get small lumps from: Oriental Arts or Inkston
They sell small amounts which should last quite a while.
Put the lumps in a small shallow china dish
To use it, spray lightly with water, and just take the colour off with a brush.
Let it dry out after use. It will gradually get wrinkly-looking, but that does not affect its use.
Leave the dish open.
Remember that natural rattan is poisonous, so wash your hands after touching it and do not ingest it.
Mineral Blue and Green
If you want to use these, you have a choice of form – tubes. chips or powder: have a look at our CBPS notes on colours.
Tubes are the most convenient, chips are fairly easy to use, powder most difficult. We have listed the Marie tube numbers for convenience. Tubes are available from eg Oriental Arts.
Inkston sell blue and green “chips”, but you may need a mortar and pestle to crush them for use. They are harmful if swallowed or inhaled (including their dust) and you should wash your hands after touching. Note any hazard labels or warnings on their website.
There are slightly different shades on offer, “Gold Colour Pearlescent” and “Mellow Gold Shimmer Pearlescent” for example
Amazon also sell some heavier duty gold card/paper up to 250 gsm but beware of the very shiny varieties that do not look good as a painting background.With any of the metallic finished papers I would advise mounting them on a firm back prior to painting. They are not absorbent and will buckle and curl when wet with ink or paint, neither of which will spread as it would on any of the customary Chinese papers
Initial practice on a spare piece is highly recommended and I would also suggest that thicker than normal ink and paint are used as this will aid adherence to the paper and give improved coverage (if anyone managed to obtain some of the gold paper he had suggested, those who attended Qu Lei Lei’s on-line workshop last year of blue, green and gold landscapes, will understand what I mean)Depending on what effect is required, for one of the paintings I used letter paper, printed with an antique effect rather than gold, eg “Motif Letter Paper – Antique and History” again available on Amazon. There are several different colour options and effects available but, once again, really need to be pre-backed before being put to use for paintingThe alternative to using ready made gold paper is to apply a coat of gold paint to a sheet of Chinese paper that the artist would normally use, and then letting it dry completely before adding any artwork. This can have a couple of drawbacks, the gold is inclined to rub off, and it can affect the texture and/or the absorbency of the paper’s surface. However I have seen this method used with some degree of success
Jackson’s Art has individual colour gansai. There are gansai sets on Ebay.