Print companies have been warned that, although not all increases have been confirmed, most merchants will make increases in the region of 8-12% from 6 April.

Last month, several manufacturers increased their prices, blaming rises in the cost of raw material and production.

Antalis, and its sister company James McNaughton Group, said it would raise its prices by 8-10%, dependent on the grade.

The group said this would affect coated and uncoated graphic papers for sheets, reels and cut-size grades.

Howard Smith Paper said the full extent of the proposed price rises on its pricing strategy was not yet clear, but it is likely to raise prices between 8-12% for coated and uncoated grades for stock and direct mill deliveries.

At Robert Horne, the  increase is expected to be in the region of 8-10%.

Printers have hit out at the proposed rises, accusing merchants of profiting from the mills' price hikes.

The Ink Shop managing director Stuart Mason said: "It will have a huge impact on the industry and will be worse than previous increases because it's so substantial. Merchants seem to be using it as an excuse to increase their margins, as the percentage increases from merchants is actually higher than those quoted from the mills.

"I can't see how we can then put these increases across to our customers - as soon as you mention price and increase in the same sentence, clients start looking around elsewhere."

Giles Lock, managing director at Top Print, said the rises could be mitigated if merchants didn't allow themselves to be hit by such staggering amounts of bad debt.

"The issue for printers up and down the land is that paper price rises often have to be absorbed as it isn't possible to pass on blanket increases – customers would simply walk if we announced a ‘take it or leave it' increase," he added.