Currently there are no universally used standards for carbon labelling, and therefore there is a great deal of variation. Printers are being asked by their customers to seek 'carbon neutral' status, but the boundaries within which they calculate their emissions or 'carbon footprint' (a measure of the impact of the activities of an organisation, individual or even a country) may quite legitimately be different.

Printer A may include staff travel to and from work as well as business travel and transport of work in progress and finished goods; printer B may just include business travel and deliveries. Printer C may include all the emissions related to waste disposal, whilst the others do not. 'Carbon emissions' may be taken fairly literally, meaning just emissions of carbon dioxide (CO2), or it may be taken to include all greenhouse gases, corrected to their 'carbon equivalence'. For example, 1 tonne of methane, a gas given off when things break down in landfill, is calculated as being 21 tonnes of CO2, as it is 21 times more powerful then a greenhouse gas. Or 25 times - depending on which information source you refer to.

So even before people start looking at offsets, the variables are considerable.

'Offsetting' carbon emissions involves investing in a project to reduce the equivalent weight of carbon equivalent emissions elsewhere: for example, by investing in renewable energy, or forestry projects. This topic is quite controversial, and more information can be found on the sites linked to the right of this page.

Buyers are also asking for 'carbon neutral' products, but again, there are currently no set means of calculating the emissions related to a product or service. DECC - the Department of Energy and Climate Change - published a formal definition in 2009. It is: "Carbon neutral means that - through a transparent process of calculating emissions, reducing those emissions and offsetting residual emissions - net carbon emissions equal zero".

There is also a Publicly Available Specification that was developed by BSI, Defra and the Carbon Trust: PAS 2050: Specification for the measurement of the embodied greenhouse gas emissions in products and services. This offers a common standard for everyone to use for their calculations when labeling products, and will therefore allow comparability and benchmarking. It will be a while before it can be used fully, as everyone in the supply chain will need to calculate emissions for their products - inks, paper, consumables and so forth. But eventually it will help people to specify for lower emissions - because it will be possible to see what difference changing the spec makes.

There are two labels available in the UK that do specifically require reduction of carbon emissions - which is by far preferable to simply offsetting.

The Carbon Reduction Label is based on the PAS 2050 system for calculating emissions. It shows the total greenhouse gas emissions from every stage of the product's lifecycle, including production, transportation, preparation, use and disposal as a CO2 equivalent. You have to commit to reduce the footprint of the product over the next two years.

The other label is the Carbon Trust Standard. This is for organisations, rather than individual products, and is based on the GHG Protocol. To achieve this, you have to show a footprint reduction - your current emissions will be compared to your average over the previous two years; you have to have a low carbon policy and to demonstrate that you have a  management system in place; and you have to be monitoring and recording energy and emissions.