Australian FDC Guide
An illustrated guide to Australian First Day Covers.
Identifying Self-adhesive Stamps on Covers
Australia Post first issued self-adhesive stamps in 1990. The first self-adhesive stamp was a reprint of the 41c cyclcing sport definitives series (16 May 1990). Since this first issue there have generally been First Day covers issued and it's sometimes hard distringuish between the self-adhesive and gummed stamp FDCs. This page looks at the different ways to differentiate between them.
According to Australia Post (on their Stamp questions page) it all comes down to the perforations; with different perforations for the self-adhesive stamps to the gummed ones, with the current self-adhesive stamps containing a semi-imperforate edge eith on the top and bottom of the stamp or on both sides. This is certainly one way to identify them, but not the only one. The following sections look at the different ways.
Note that whilst there have been self-adhesive stamps issued regularly since 1990, often in an issue with gummed stamps and minisheets, Australia Post did not always issue FDCs for the self-adhesive stamps. Whilst there may be a FDC for a self-adhesive stamp, it may be a collector created one rather than an official Australia Post FDC.
Since the Australian Heroes of Grand Prix Racing issue in Oct 2004, the self-adhesive stamps have generally had part of either the top and bottom of the stamp or both sides of the stamp imperforate. The image to the right shows the two Melbourne 2006 Commonwealth Games stamps; self-adhesive on the left, gummed on the right. You can see the semi-imperforate section on the top and bottom of the self-adhesive stamp.
You can also see the variation in perforation sizes between the stamps (more on this below).
Border on Self-adhesive
During the early 2000's a number of issues that had both gummed and self-adhesive stamps differentated them by having a border trimming the image on the self-adhesive stamps, sometimes white and sometimes semi-transparent.
The image shows three of the 2004 Australian Railways issue. The top three stamps are the self-adhesive ones from the self-adhesive FDC. The bottom three stamps are from the gummed FDC.
Cover with Strip or Block vs. Separate Stamps
When Australia Post issued sheets of gummed stamps in se-tenant pairs, blocks or strips, and the same stamps (same images, denominations etc.) as self-adhesive stamps, the official FDCs will have the gummed stamps joined and the self-adhesive stamps separated on the covers.
For example the 2004 Australian Railways issue (see above) had five gummed stamps in a se-tenant strip, so the gummed cover had a strip of three and a strip of two (to fit onto the cover). The self-adhesive cover had the stamps in the same arrangement but separate.
Similarly the 2004 Renewable Energy issue (shown to the right) had the four gummed stamps in a se-tenant block of four in the gummed sheets. The gummed FDC had the block on it (bottom of image). The self-adhesive stamps on the self-adhesive FDC are arranged in the same way, but not joined (top of image).
Subset of Stamps on Covers
When Australia Post released stamp issues of different denominations, they normally only issued self-adhesive stamps at the standard postage rate at the time. This means the gummed FDC will have all stamps in the set (often four or five), whereas the self-adhesive FDC will only have the self-adhesive stamps (often one or two).
For example the 2000 Paralympic Games issue included five gummed stamps; two 45c stamps (the standard postage rate) and three 49c stamps. There were only two self-adhesive stamps for the issue, the same as the 45c gummed stamps. So the gummed FDC features all five summed stamps, but the self-adhesive FDC only has the two self-adhesive stamps.
This approach relies on knowing what stamps were released in an issue. I'd recommend the Australian Stamp Catalogue as a great source of information for stamp issues.
Perforation Size and Stamp Corners
The common difference between the gummed and self-adhesive stamps is the perforation size and the effect this has on the corners of the stamps.
The image to the right shows two 45c frog stamps from the 1999 Small Pond issue. The self-adhesive stamp on the left has larger perforations than the gummed stamp on the right. This results in the gummed stamp having a more defined corner than the self-adhesive stamp.
This appears common across all gummed and self-adhesive stamps I've looked at.