Royal Mail is proposing a shift from weight to size in determining postal charges. Large yet light weight mail packs would cost up to 33 per cent more to post (see feature, page 47).
Royal Mail said the increase in price would reflect the reality of what it costs the carrier to handle larger, non-machineable packs.
A spokesman for the UK's largest agency, WWAV Rapp Collins, said: "What Royal Mail is trying to do is incentivise people to produce mail that is machinable and penalise those items that aren't. The consequence could be a serious stifling of creativity since we are all trying to produce work that stands out from the crowd."
Royal Mail is still consulting customers on its plans, discussions that are due to end on 28 June when Postcomm, the regulator, begins its review of Royal Mail's proposals.
The body representing clients, the Incorporated Society of British Advertisers, is also critical of the proposals because of the constraint they would put on creativity.
Envelope makers too have voiced their concerns to Royal Mail. "Our worry is that the larger sizes, particularly C4, have been the fastest growing sector of the market but that this growth will slow if they cost more to mail, said Mike Dellar, chairman of the envelope manufacturers' association EMMSA.
He is calling on Royal Mail to invest in machinery to mechanise the handling of larger packs.
Royal Mail said it would listen to these concerns. In the meantime, Debbie Moffat, Royal Mail's head of agency development, urged creatives to think of any constraints on pack size as a creative challenge.
She commented: "All media have constraints. In a TV ad you have 30 seconds, and if you want 60 seconds you pay more but you use it. And no one says 30 seconds stymies advertising creativity. If size is going to be a dimension of mail media, then be creative. DM creatives can, and they will."