Here's information from the Singapore Government Customs website -
There are four broad categories of dutiable goods in Singapore - intoxicating liquors, tobacco products, motor vehicles and petroleum products.
Where the goods are dutiable, ad valorem or specific duty rates may be applied. An ad valorem rate is a percentage of the Customs value of the imported goods such as 20% ad valorem. A specific rate is a specified amount per unit of weight or other quantity such as $352.00 per kg.
GST is applied on an ad valorem basis on all dutiable and non-dutiable goods. The GST taxable is calculated based on the CIF (Costs, Insurance and Freight) value plus all duties and other chargeable costs, whether or not shown on the invoice.
Duties and GST may be suspended up to the point of consumption if they are imported or manufactured under the various Customs schemes.
And since lingerie/clothing falls under non dutiable goods, here's the related link of info for importing this product Link hidden: Login to view
Related news/articles - Link hidden: Login to view
Hope this helps. :)
Welcome to SaleHoo!