A collection of Singapore's first ever banknotes, known as the Orchid Series, has topped an Asian coin sale in its country of origin.

The undervalued banknote market is seeing increasingly strong results

The set, which totalled more than 420 pieces, sold for an impressive $27,268 on July 27, making a 4.6% increase on its initial valuation. It featured 27 "golden number" banknotes (which are valued for their lucky serial numbers), 27 error notes, two specimens, 344 notes with minor errors and 20 normal notes.

The Orchid Series banknotes were the earliest to be issued for circulation in Singapore, and were in use between 1967 and 1976. Each note of the nine denominations is decorated with an orchid design as the country's national flower, the Singapore coat of arms and a lion head watermark.

Following the Orchid notes was a complete collection of Chinese coins from 1986, which were in mint condition and sold with the original packaging. The seven piece set included a medal showing the tiger, that year's lunar animal, and brought $18,000. The price represents a 20% increase on its $15,000 high estimate.

Also featuring was a 1916 $10 Straits Settlements banknote, which sold for $13,000 against an identical low estimate. The Straits Settlements was the name given between 1826-1942 to a group of British territories, including Singapore, located in Southeast Asia.

Now is a good time for banknote collectors, with more auction houses featuring them as a larger part of their catalogue and some great results seen at auction recently.  With the market still undervalued and prices on the up, now is the time to invest. Collectors will soon have the chance to bid on more Asian banknotes in an important August 23 sale in Hong Kong.

See our full range of investment-grade coins here, for some stunning additions to your collection.