Australian Stamps  have used 11 different watermarks in the early years . However some of these were only found on State stamps. Watermarks can be found on Australian Roos  and George V Issues starting in 1913 and seem to finish in use around 1955

I would very briefly like to talk about How to find Australian watermarks and hopefully give the reader a chance to answer the question

What watermark is this?

Watermarks are usually described  either by type or by Number/description. Pictured below are some of the different watermarks (WMK) for Australian Pre- Decimal Kangaroo on Map Stamps

• First Watermark is often referred to as Type 6
• Second Watermark as Type 7
• Third Watermark as Type 8
• Small Multiple Watermark as Type 10
• Cof A as Type 11

Here is an example of what 1st watermark (WMK) looks like on an actual stamp

How to Find Australian Watermarks

The first method that you can try is to hold the stamp up against the light looking at it from the back side and you may be able to clearly see the watermark and match it to the Type. Whilst this can be a quick and easy method, there can be times when it is very difficult to see a clear image and you may need to resort to using a detector such as the Morley bright Unit. (these can be purchased on Ebay).  They use a liquid bubble which highlights the watermark but even these units can take some practise and experience before you can define the watermark with any confidence.

So once you have answered the question What Watermark is This?, you are well on the way to determining the value of your stamp as often the watermark and the perforations will take what looks to be a common stamp into a much rarer area and hence higher value.  Good luck in your searching!