This is the most cost effective method of delivery, but it does not offer any tracking facility or next day guaranteed delivery (up to 2kg in weight). Royal Mail also do not offer a guaranteed delivery time on first class packages, but they do aim to delivery by the next working day.
Royal Mail also place restrictions on the volume of their First Class postal service, which means, when orders exceed a certain predetermined dimension, it will be necessary to upgrade your delivery to a courier service, which will be an added cost of £7.56. Unfortunately this is dictated by Royal Mail, and not Photoshop Digital UK.
If this does occur, we will contact directly, to let you know, before your order is processed.