Awareness for stone paper is growing, but many people still haven’t held stone paper. Stone paper is a sustainable alternative to tree-based paper made of 80% stone powder (calcium carbonate) bound with 20% plastic (high-density polyethylene). The Pebble Printing Group has had the privilege of printing two runs of New Zealand’s first stone paper book. This project provides great insights for publishers who want to use stone paper for books.
Why Stone Paper?
For educational publisher EduMaxi Limited, the sustainability of stone paper was connected to the theme of their book, Flint & Fern: The Karma of the Condor. A lesson in this story is to empower young people to break away from the status quo. This reflects the spirit of stone paper, a radical innovation in printing materials.
Using stone paper, EduMaxi was able to eliminate trees, water, seventy percent of carbon emissions, and reduce oil consumption compared to traditional tree-based paper. Bleach is not required to make the book white. Production is also completely waste-free. Click here to view an sustainability study about stone paper. Scroll below to the Pebble ID™ section to learn how we communicate this sustainability.
The sustainability would not be as important if the material itself didn’t make a difference for the reading experience, as per the theme of the book. Stone paper has a noticeably higher smoothness and whiteness than traditional paper, producing crisper text without yellowing with time. Like the radical innovation encouraged by their book, stone paper is an unmistakable improvement over traditional paper.
Printing on Stone Paper
Due to stone paper’s powdery structure, it has technical differences for a printer. Pebble Printing Group stands out with specialized stone paper printing experience. Here are a few of the obstacles we had to overcome to produce this stone paper book with perfect quality.
Beginning with paper selection, we recommended a slightly higher weight due to stone paper’s 10 percent lower opacity than traditional paper. Our recommendation was RPD 120 (144 GSM, 120#). With stone paper’s higher density, this is a sweet spot to make the weight comfortable. For the cover, we chose RBD 300 (450 GSM, 166#) to ensure proper stiffness for a high quality stone paper book.
Stone paper is waterproof with a special coating that acts like fiber-based paper. Printing ink likes the surface of stone paper, but it cannot penetrate into the interior of the material. For a printer, this means ink film density is key. For the black and white interior, this is simple. Controlling the ink density of one color can be done with one button. This is one reason why novels are most suitable for stone paper printing.
For the cover, this is more difficult. Full-color images usually require four layers of ink: cyan, magenta, yellow, and black. These are known as process colors (CMYK). The cover was printed using a high-weight stone paper that uses a recipe of 60% stone powder to 40% HDPE. This means that the cover has an especially slippery printing surface. When printing the cover, we use approximately 70% less ink to make the same color appearance and saturation as tree-paper. Color accuracy is the most difficult step for stone paper printing. It requires an expert printer. To ensure that the ink stays on the surface, we used a matte lamination. For a perfect result without lamination we could use UV-curing inks, but these can be more expensive than offset inks.
Pebble ID™ System
Printing on stone paper does not make it obvious to the readers why stone paper is sustainable. In fact, some readers are skeptical when they see a twenty percent component of plastic.
This is why we introduced the Pebble ID™ system with the first reprint of Flint & Fern. Using a Pebble ID™, readers can directly see the resources saved using this innovative material and get personal assistance for their questions. They do this by following a link to our Pebble ID database, or scanning a QR code on the copyright page of the book.
Click here to view the Pebble ID entry for the book’s reprint.
The first book was delivered as expected, and we were proud of our work. In quick succession we received the request for a reprint. However, during the process of the reprint, the global pandemic worsened and global shipping was destabilized. For this, we worked closely with EduMaxi, providing frequent updates on the status of the boat. This is our responsibility as a great printing partner, regardless of what material we are using.
We are especially excited that this publisher’s book was featured in the local news, and that the author was satisfied with the quality of New Zealand’s first stone paper novel.