Embossing (raised impression) and debossing (deep impression) are techniques to print without ink. The paper has to have enough fibre and depth to take that impression. The softer the paper, the more it gets compressed and the impression will show less on the reverse side. Soft papers made from cotton fibres are ideal. Those made from wood fibres are harder, do not compress as much and will give more show-through on the back of the page.
Printing with such high pressure will damage normal type eventually, so usually de- or embossing is done with etched metal blocks (clichées).
We printed this poster with letters made from Plakadur, a resin used by Berthold for type larger than 8 cicero/96 point. It is harder than wood type, but not as hard as metal. Our Fedrigoni Rosaspina is made from cotton, so the pressure of the type compresses the fibres, making the debossed areas smoother than the unprinted surface. Both the outlines of the letters and the contrast between the surfaces achieve enough definition to make blind embossing an interesting alternative, at least for large sizes and simple motives.
Nevertheless we decided to use transparent ink to print this 3rd edition of our bestseller Use your fucking brain, to strengthen the effect of the contrast. Buy the poster here.