4th Definitive Stamp series, Biodiversity
The 4th Definitive was originally printed with gum arabic (2007, glossy white back, 14:13½).
The 4 additional values (issued 2008) are the same. The 12 original values were then reprinted in 2008 with PVA gum (creamy yellowish back). SG does mention all 12 stamps. The Standard Mail stamp (Web-Footed Gecko) alone was reprinted in 2010 and 2011 again. The 2010 reprint is technically the same, but the 2011 reprint was by Southern Colour Printers also with PVA gum, but different perforation, 14.