Security Threads
Featured on:
• Orchid, Bird, Ship, and Portrait series all denominations
• 1996 MAS25 $25, 1999 M2 $2, 2007 CIA40 $20, and 2015 SG50 $10 commemorative notes
A security thread is a thin strip embedded into a banknote to prevent counterfeiting. It typically runs vertically and is inserted during the papermaking process, becoming a permanent part of the note. On Singapore banknotes, security threads may appear as solid or segmented lines, and may include text or symbols that are visible when the note is tilted or held up to light.
The design and complexity of security threads have evolved over time. In the Orchid series, all denominations featured a solid metallic thread, visible as a continuous dark line when backlit. The $10000 Orchid note had two solid threads for added security. In the Bird series, all denominations originally used a solid thread. Later batches of the $1, $10, and $50 notes changed the thread to a segmented one instead, while the $1000 and $10000 notes went further by including both a solid and a segmented thread.
The Ship series initially featured a single solid thread for all denominations. Later, the $50 and $100 notes adopted segmented threads, and the $50 note was eventually upgraded to a clear-text thread. This thicker thread displayed the note denomination and “Singapore” in various languages when the note was tilted or held up to light.
The Portrait series introduced a more advanced thread in all paper denominations—a variable-image thread. Depending on the viewing angle and lighting, we can see either the note denomination and the word “Singapore” in multiple languages, or symbols like the Lion Head symbol or MAS logo. For polymer Portrait notes, physical threads could not be used, so a printed security pattern shaped as an outline of Singapore island was added as a visual substitute.
Among commemorative issues, only the paper-based 1996 MAS25 and 1999 Millennium M2 notes featured real embedded security threads, with the MAS25 note using the words “MAS 25th anniversary” on the thread. Later polymer commemoratives, such as the 2007 CIA40 and 2015 SG50 $10 notes, reused the outline of Singapore island in place of a thread. The remaining polymer commemorative notes did not include any form of security thread, preferring to adopt other security features.
