Stamp Grading

Understanding the Elements of Stamp Grading


Stamp collectors are faced with a myriad of terms and symbols to describe the stamps they are considering for purchase. And when operating within a modern landscape of online dealing and often internationally thanks to the www, a further layer of potential confusion can develop as a different set of codes and symbols are thrust upon us.


By developing a sound understanding of grading principles you will be able to more readily understand and interpret the terms and symbols no matter what part of the globe the seller is from. You can ask direct and specific questions. This knowledge puts you ahead of the pack as you are able to readily determine fair value – which after all is the significant fundamental to most buying decision.



Whilst this article will make reference to Australian stamps from the Commonwealth period, the same general principles apply to stamps from mostly anywhere in the world for this period. It is provided as a guide to assist you build your basic grading skills. I have not included Colonial stamps as very different standards are required for these issues and they are beyond the intended scope of the article. These wonderful stamps deserve their own space.


To further develop your grading skills I can’t emphasis enough the importance of  building relationships with reputable dealers who are prepared to give you some of their time. They can fast track your learning curve like nothing else. Attend the nationwide stamp fairs, 



Personally I like to lay the stamp under consideration on a black background, I feel this brings it into a sharp visual focus and highlights the elements that make up the grading assessment.



Refers to how the impression or image sits within the entire landscape of the stamp. You will see spelling variations of the term centring, but within Australia centring is the most common. They all refer to the same thing.


The various Australian issues have different average centring reference points. The more you study the stamps, the more obvious this becomes. As a general principle, the older the stamp, the more difficult it becomes to find it very well centred. Hence the price premium attached to these stamps.


To support this, I recommend a visit to the Post Masters Gallery next time you are in Melbourne. Admission is free. Here you will find The National Philatelic Collection on display. Study the Kangaroo, KGV and early General Issue sheets. You will see how the technology of the day resulted in those sheets being perforated inaccurately which caused the variable centring. Hence only a few stamps on each sheet are very well centred and it highlights just why these stamps are so difficult to find in the market place. I would respectfully suggest that premium centred Kangaroos & KGV issues are still way undervalued given the obvious scarcity there must be.





1920 Single Wmk, 1/4d KGV head. This stamp represents average centring for a KGV Head issue and should not attract a discount for centring. As printing technology improved over the decades, so did the centring.



Perforations (Perfs)

Unlike centring, perforations on Australian stamps have generally been of a good standard. At various times paper shortages, WWI for example, resulted in usage of poor quality paper that the perforating machines had trouble “biting” into. Hence the term “Fluffy Perfs”. For example Second Watermark Kangaroos are notorious for this. Some of the KGV stamps, both Heads and General Issues suffered also from this and for other technical reasons.





1914 wartime printing of 2nd Watermark Kangaroo. Paper shortages led to usage of less suitable paper. The perforating machines had difficulty "biting" cleanly through the paper resulting in what is now called "fluffy perfs".





1932 Australian icon stamp - the 5/- Bridge. A General Issue stamp from the KGV period it has typical poorly defined perfs. This is quite common to stamps of the period. The centring is well above average and makes it worthy of a 20%-30% premium.


Freshness & Colouring

Often underrated, but of major significance, the freshness factor will be determined by storage practices.  Incorrect storage will result in colour fading, oxidisation, a dull flat appearance etc. Colouring relates more to the strength of the initial printing impression combined with the ink mix. Bearing in mind that each print run brought a new combination of printing variables together. It’s what makes the early Australian issue so absorbing.






9d 3rd Wmk Kangaroos - same stamp, different printing. Note the freshness and rich colouring of the Monogram piece when compared to the Imprint pair. It's simply luscious!




There is a wide range of views relating to the importance of the gum. I know collectors who just wash it off (not recommended) because they want to freshen up their stamps, through to those who rate it above the face of the stamp (I wonder if they display their stamps gum side up). As with most things in life, somewhere in between works best.



Rust, tone spots, foxing, oxidisation, gum tropicalisation, tanning, two tone gum, brown gum, gum spots etc. You’ve probably heard them all at some stage and most of them are the same thing under a different name – sounds horrible and most of it is. What it often means is that rust spores have grown on the gum. They can spread through the stamp and even the entire collection. Some light gum tanning isn’t necessarily a bad thing, and proper rehousing is a worthwhile exercise in the right circumstances. Talk to your dealer about this if you have concerns with your collection. It may not be too late, but do have it professionally assessed. Important - don’t under any circumstances place mint stamps in second hand housing sheets if you don’t know what has been previously stored in them, there may be rust spores laying in wait.




Sent down to a leading Melbourne dealer from a Queensland estate for valuation. The collection included a number of scarce booklets and many valuable pre-decimal full sheets. Properly stored this was a $10,000+ collection - tragically unsaleable as it was full of rust due to poor storage practices.



Hinge Marks

This refers to the mounting remainders or marks on the back of the stamp. Up until the introduction of hinge less mounts, stamps would be secured in the Album using a stamp hinge. This is a small rectangular slip of paper with gum on one side, the idea is you moisten that and affix it to the gum side of the stamp (cringe), then moisten the other end and stick that on the Album page. Some hinges can’t be removed fully and hence become a remnant (remainder) on the gum. Better quality hinges can be peeled off the stamp leaving just a trace or shadow of where they have been.


In respect to grading & pricing these states of hinging are covered within the abbreviated descriptions you will see in catalogues and dealer price lists. It is an area that causes a lot of confusion even for experienced collectors due to different reference terminology used. I’ve certainly been guilty of using a range of terms and am currently updating my stock to the following set of standards. They cover the range of hinging you will encounter, are easy to understand and allow for a distinct pricing differentiation. Importantly they relate to the gum side grading element only.


MUH – Mint Unhinged – the stamp has never been mounted.

MVLH – Mint Very Light Hinge – the stamp has been previously mounted but with a peelable hinge that has left only a trace upon removal.

MLH – Mint Light Hinge – the stamp has been previously mounted with only light hinging evidence visible upon removal.

MH – Mint Hinged – the stamp has a moderate size hinge remnant that may be faintly visible when viewing the front of the stamp.

MHH – Mint Heavy Hinge – the stamp has a heavy hinge remnant that has caused a kink to appear on the face of the stamp.



The grading term that leads to most confusion is the word Mint.


What does the term Mint mean? That’s a bit like asking what does a particular piece of art mean. – Answer, it’s how you are wired up to interpret it. It’s just too general.


Pricing catalogues that use the term Mint are generally referring to a lesser grade Mint Hinged stamp. Where this becomes confusing is that some are referring to the gum only, (which is confusing in itself – Mint what? Hinged, unhinged, heavy hinge?) others include grading elements such as perfs and centring into the Mint description equation. Some collectors think it’s a stamp with full gum, and why not? You can imagine the confusion when presented with a stamp that has a massive remnant and a couple of nibbled perfs!


The important point is to have a clear understanding of what the particular seller means by their grading terms. Most reputable dealers provide an explanation with their grading terms.


Paper Inclusions

The term refers to natural imperfections embedded in the stamp.  These often show up as small specs on the gum side of the stamp, sometimes they show through to the front. When the spec are spots and become visually unpleasant, the stamp should be downgraded appropriately. More often that not they are a non-issue.





The front is showing a rust spot off the SE coast of Victoria, a definite negative. The back shows a quite typical inconsequential paper inclusion spec off the Nth Qld coast. There also appear to be a stain next to Brisbane, a definite negative.


Gum bends

A bend is where the stamp has taken on a trough like appearance, this is sometimes referred to as a gum curl. It occurs in stamps with particular paper and gum characteristics. E.g. many KGV commemorative issues have gum bends. They are naturally occurring and should not adversely affect the stamps value.


Gum disturbance

Refers to gum of a streaky and unnatural appearance. It is caused by the gum reacting to outside forces either natural or unnatural. It can take on many forms and is a big negative.



Is the process where the original gum has been washed off the stamp (usually toned or disturbed) and the new applied. Watch out for this one! Some regums are difficult to pick and makes for a strong case to purchase only from reputable dealers who are members of trade associations. They guarantee their stamps and you have recall through the trade body if a dispute arises. The old adage “if it seems too good to be true – it probably is” rings particularly true when it comes to apparent stamp bargains and especially the more valuable ones.



Look closely at any stamps under consideration for faults. Prices should be discounted significantly for visually obvious faults e.g. missing perfs up to 90%, then scaled down to say 10% for a light fold visible from the gum side only. It goes without say, but I will anyway, that for collectors wishing to assemble better grade collections – avoid stamps with faults, no matter how cheap the stamp may seem.


Creases & Wrinkles

Creases can occur naturally in the manufacturing process of the paper or through mishandling of the stamp. A light fold comes about only through mishandling and if it can be seen from the front it should be referred to as a crease.


Gum wrinkles occur naturally in the paper manufacturing process and provided the paper fibres are not broken the wrinkling will not show through to the front of the stamp. They give the gum a squiggly look. Where the fibres have broken they will show through to the front of the stamp. This is a negative.



There are two main types, closed tears and open tears. The latter is self explanatory; the former is a tear that may not be visible to the naked eye. You may need to view the stamp under magnification to pick up on these, as the two sides of the tear overlay each other, hence the term closed tear. Both are serious faults.



These are caused when a non peel hinge has been removed and taken part of the gum with it. A semi-transparent patch is created where the gum once resided. Sometimes this is obvious at a glance, other times the stamp needs to be held up to the light for detection. It is an easy one to be caught out on. If you’re buying on a “bargain” type auction website, sight unseen (other than a tiny little scan and a vague description) be sure to check beforehand that the seller will provide a refund for misdescriptions. A lot of this type of “bargain” material is offered through these mediums. More often than not the seller wouldn’t even be aware of the fault. They just thought they bought it cheap in the first place!



These are tiny holes in the stamp that can be seen by holding it up to the light. Like most faults there are degrees, with some quite apparent and others are of a semi-transparent nature and far more difficult to detect. They are two main causes, a tiny rust spore has eaten though the paper, or miniscule paper imperfections have become dislodged leaving a tiny hole.





What an ugly lot! Top left - perf tones and heavy hinge remnants. Top right - more rust and the left unit is creased. Bottom left - serious gum disturbances. Bottom centre - heavy oxidisation. Bottom right - a nasty thin to upper section of the stamp. Pass!



Grading Elements Summary


Centring – Unless you have a lifetime to spare and a massive budget, forget premium centred MUH Roos and KGV Heads. You can expect to pay from 50% to a 200% premium for these stamps.  If you find one without a price premium attached to it, snap it up, it won’t be there for long. If you don’t want it, call me!!!  Avoid stamps where your eye is immediately drawn to the centring i.e. image frame touching perfs, uneven centring on three sides etc. If you go to sell it, remember the next buyer will see the same thing. If you are happy to collect this grade, you should discount the price by around 70% to the price of average centring for that particular issue.


Perfs – Look for clean cut and well defined. This is a reasonable expectation for most issues. Be more flexible on stamps produced 1914–19 (WWI) and many of the KGV General Issues. The paper and perforating practices resulted in less than ideal perfs. It is probably incorrect to say avoid “fluffy perfs” on the grounds they are faults and I know many collectors who quite like them. The reality is they were produced that way and strictly speaking it is not a fault at all. Generally they sell at a discount of 20-50%. Nibbled, Short and Damaged perfs (in that order) are a negative and attract discounting between 20-90%.


Freshness & Colouring – Look for stamps with a clean & fresh appearance. Rich colouring is worth a premium. Avoid stamps with an oxidised, stale and dirty appearance. They should be discounted from 20-80%.


Toning - Seek out stamps with clean, original undisturbed gum. A very light even tan is ok, but where you see spots leave it alone. Should it be a scarce stamp that you just must take custodianship of, you could isolate it within a separate mount within a ‘Hagner’ type sheet. Provided it is stored out of humidity the rust spores should remain dormant.



Hinge Marks - Be sure you understand the sellers grading annotations. If you are looking to compile a better grade collection avoid stamps with hinging that noticeably affects the front of the stamp. Heavy hinging should be discounted to around half the price of MLH pricing given all other grading elements are equal.


Paper Inclusions - A speck or two on the gum side is nothing of concern. Where it shows through to front of the stamp a discount of 10-50% should be applied depending on the visual severity of the inclusion.


Gum Bends - A non issue providing it is common for the issue. If not, it warrants a closer look. Could it be a fault of another kind?


Gum Disturbances - A significant negative and depending on the type of disturbance regrades the stamp downwards by up to 80%. This is particularly true where it has been unnaturally affected (human intervention).


Use this knowledge to determine:

What to buy, what to avoid & when to buy it.


Blue Owl Top Tip - Train your eye to recognise what is the average grade for the stamp you want to purchase and what the market price for that is. With this reference point in mind go shopping for the best value within the framework of your collecting standards.


Stamp Collecting is much easier and more fun when you have a strategy! Important - Build relationships with reputable dealers who will give you some of their time. The free advice will save you a fortune in the long run.


When is the right time to buy?

Now! It’s simple really. If you’ve followed your plan and found the right stamp, don’t procrastinate. You’ll kick yourself if it’s gone tomorrow, particularly when it represents more than fair value. If held by a dealer with whom you have established a relationship, you could in all likelihood secure it on a deposit if you’ve already blown the monthly budget. The main thing is to secure it so you can start looking for the next one!