So what do you do if you want to add on a little extra to each product depending on the weight? Normally we would suggest adding this extra cost directly into your cost price however at times for a number of reasons this wouldn't be possible.
In the event that you can't do it this way you can setup new rules to apply this extra value for you. To learn how to setup multiple rules read this helpfile.
In order to do this you would setup a format for each of your postage bands (Ie, 1-5 Pounds, 5-10 Pounds, 10-20 Pounds, etc) and then create rules for each of these formats. By applying the format to the products which have these weights you can then use the rule to manipulate the minimum price.
For example you setup your 1-5 Pounds rule based on Cost Price (e.g. minimum price = cost price + £0 + 0%). Then for 5-10 Pounds rule you have an additional value in them (e.g. minimum price = cost price + £1 + 0%) and continue this.
By doing this you can gradually include an additional cost for each weight and quickly update them if there is a change such as the Royal Mail increasing their prices.