Printing with HP 7720 at the correct settings. Even after many days of drying, if I touch the paper in the printed areas, the ink smudges. The same happened with the Dual Side High Glossy A4 (21x30) 160gr/m² papers from MediaRange. These two are the only products from the company that I have checked. Searching through international reviews for the product, I noticed that others had the same problem, and with other printer brands.

Edit: Eventually, on an Epson printer with dye ink, the printing was done without the ink smudging, with excellent results. The HP printer had pigment ink. Apparently, this was the problem, but it is not mentioned anywhere by the photographic paper company.