Numerous Chinese stamps depict Sun Yat-sen, and a representative collection can be acquired with little trouble. These may conveniently be divided as the definitives, provincial issues, overprints, and commemoratives, but there is much crossover between these categories. Definitives The material below recognizes 12 definitive issues of Sun Yat-sen stamps produced by China during the 1930s and 1940s. The Stanley Gibbons Catalogue lists fourteen separate issues, but list the regional issues as additional. Other catalogues, such as Chan, may count reused designs or the printings by different printers as constituting separate designs. Because of the complexity involved with these stamps the organization below of these issues is motivated by making the identification of these issues as simple as possible for people who are not yet familiar with these stamps. Chan recognises 26 separate Sun Yat-sen definitive issues up to 1949, including provincial issues, and is perhaps the most logical and rigorous of the China stamp catalogues in this area. First issue The first Sun Yat-sen definitives were issued in 1931, and were recess printed by De La Rue & Co. of London. In this issue the portrait of Sun Yet-sen is flanked by Corinthian columns. It only exists in the 1¢, 2¢, 4¢, 20¢, $1.00, $2.00 and $5.00 face values on unwatermarked paper, perforated 12½ by 13. The three high values are bi-coloured. Because the ring inside the sun emblem appears as two rings this is commonly known as the "Double Circle Issue". The double circle was an error, but existing stocks were allowed to be used. Because it was soon replaced fewer legitimate overprint varieties exist on this issue than on the succeeding issue. Second issue The second issue of Sun Yat-sen definitives was also first issued in 1931, and corrected the inner ring in the sun symbol to a single solid circle. The 1¢ value was not issued in this design, but all the other values in the first issue were reprinted in the same colours. Additional values of 5¢, 15¢ in two colour varieties, and 25¢ were also added. In 1946 the same design was used for monochrome $1.00, $2.00, $20.00, $30.00 and $50.00 values necessitated by inflation. There are numerous overprints on the single circle stamp, and there are several plate varieties of the stamps with the lower face values. For those unfamiliar with the portrait of Dr. Sun, the Martyrs issue of 1932 also has Corinthian