Regardless of the photo paper manufacturer whether it is Epson, Canon, HP or even niche suppliers, photo papers commonly use one of two technologies to accommodate the ink injected by the printer heads. This technology is called the ‘receiving layer’ and it is one of the features that differentiate between true photo paper and normal copier paper.
The receiving layer is really a translucent chemical that suppliers invest many years of research and development in, as well as large amount of money to get it right. This explains the difference you notice in photo paper print results between manufacturers.
The two most common in today’s printing landscape are cast coated and pore based, whether it is microporous or nanoprous.
Cast Coated – The cast coated receiving layer is often used for budget models of photo papers such as those designed for day-to-day use. The chemical coating sits on the paper making it susceptible to smearing when using pigment inks, as the particles in the pigment inks do not penetrate the coating and has no pores to sit in.
It is worth noting that some cast coated papers that are made by special high end manufacturers do poses the technology that can cope with pigment inks, but not all of them. In most cases cast coated will work well only with dye based inks that have no particles in the ink and so these never smears after printing (what is referred to as ‘instant dry’).
Cast coated receiving layer paper is coated on regular type of base paper that may curl and be more sensitive to humidity due to the difference in expansion between the coating and the base paper when exposed to the elements.
Pore Based – Micro and Nano porous receiving layer is used in professional models that are known as photographic papers in which archival properties are important (archival = how long before the image fades, yellows or ‘disappears’). Contrary to cast coated, in this case the ink is contained within microscopic pores in the chemical that are invisible to the eye, which makes the print instant dry and reduced fading over time.
This type of photo paper receiving layer is normally based on a superior type of base paper, which is coated on both sides with polyethylene to create more stability of the paper as it is sealed to humidity and kept flat.
When purchasing your next batch of photo papers, look at the receiving layer which should be highlighted in the product description.