So let us talk for a while about the difference in Panerai sandwich dials, and Panerai sausage dials. A sandwich dial is a dial that uses layering techniques. Such a technique is not exclusive to Panerai, but they are known for such technique because they used it extensively during their early days. They wished at that time to create very luminous watch faces, and the early examples of their art show sandwich dials made using layers of three. After that, it became more common for them to use layers of two.
A standard Panerai sandwich dial has two separate discs and the bottom layer keeps the lumed material in recessed indices while its top layer has cut outs that allow the lume to shine through. When you see a Panerai sandwich dial, you will be struck immediately by the cut out, stenciled effect. In he beginning, Panerai used radium based lume, and it was patented ad Radoimir. Later on the switched to a material named Luminor, which was a tritium based lume. These days Panerai uses Superluminova on their dials. Panerai appear to have decided to slowly but surely move away from using sandwich dials. They have only beeen using the technique on special release watches, and it seems to be losing favor.
For the sausage dials, they offer great contrast to sunken indices found in the sandwich dials. The Panerai sausage dials have hour markers that have been painted on, and they protrude. For some models, the indices carved out into the dial, and filled with lume. In other options, the lume was directly painted on the flat surface. No mater the technique, the results were curvy numerals with stick markers that rose above the dial. That is why they were named sausage dials. Panerai was so well known for these sausage dials, that many people call them Panerai painted dials. Either way, we known of what it is they speak.
It is a very cool thing to place a sandwich dial watch and a sausage dial watch side by side for a comparison. The difference is seen instantly, and a greater appreciation for both is experienced when contrasted in the manner. Some love the sandwich dials because they have such deep roots in the Panerai firm. Others love the sausage dials because they are so very clear and legible from all angles. Both designs are great, and offer their own unique visual. Both styles are historic in the making of watch dials, and Panerai has always been an industry leader in thee artistic techniques.