X17 is a notebook system developed by a German company (conveniently named X17) that consists of a notebook cover with elastic rings. These rings hold up to four notebook inserts, three in the model I use. The system is not dissimilar to Midori's Travelers Notebooks. But in my opinion it is better thought-out and more practical. It is available at the X17 shop, shipping to the UK, Canada and the US is available at a reasonable rate of 9.95 Euro.
What attracted me to the X17 was the growing dislike of my Filofax. It is just too big to comfortably carry with me and the rings get in the way of writing on the left side (I am right-handed). What I wanted was a smaller package that nevertheless holds multiple interchangeable sections, such as my calendar, my todo lists and my daily log. I have been using Field Notes pocket notebooks for my daily log for years and I am quite comfortable with their size. This prompted me to slightly downgrade from the Filofax personal size to A6, which is only a few millimeters higher and about 1.5 cm wider than pocket notebooks like Field Notes or Moleskine Cahier. My thinking was that maybe I could even fit pocket notebooks in the X17.
X17 covers are available in multiple materials: Vegetable tanned leather, smooth Italian leather, regenerated leather (shredded leather offcuts that are glued together), cellulose fiber, plastic, Balacron (vinyl-coated cardboard, also used by Moleskine) and plain cardboard. Although the cardboard version would do quite well for only 3.90 Euro I opted for vegetable tanned leather in chestnut brown including three notebook inserts (blank, grid, lined), which puts a dent of 39.90 Euro in my pocket, but is well worth the price, as we will see. Calendar inserts are also available, but for the remaining year I wanted to draw my own layout or use the Field Notes Ambition 56-week diary I could never find a use for before. I also ordered the transparent slip pocket insert and a bookmark band.
When I unpacked the notebook cover I could already smell the leather, which is besides the smell of old library books a favorite of mine. The leather is smooth but not shiny and of a wonderful dark brown color with slight natural irregularities. On the inside the leather has a rougher surface. Brown stitching around the cover holds the two layers of leather together; the workmanship is excellent. As I use the cover more I expect the leather to age and acquire a few more dents and scratches.
The inserts X17 provides have rather thin paper, which causes some shine-trough but no bleed-through with extra fine fountain pen nibs. It is not suitable for broader nibs. I won't use the X17 inserts much because pocket notebooks also fit perfectly. The elastics are slipped over the cover and the opened notebook and latch into notches punched in the top and bottom of the cover's spine (X17 made a YouTube video of the assembly process). X17 notebook inserts also have these notches, but they are not necessary for a secure hold. Because pocket notebooks are a few millimeters shorter than A6 sized paper the elastic does not bend the paper on the edges.
I heard complaints about the Traveler Notebooks not being able to lay flat. Unlike the Traveler Notebook's leather the X17 cover is shaped with a spine and because it has multiple elastics there is no need to lay multiple notebooks into each other. This must be the reason why it is able to lay flat on the table. The inserts do not lay as flat as the cover because the height of the other notebooks in it push the opened pages up slightly, but they still stay open and are very comfortable to write in.
The cover of the X17 has a notch on the right side to snap the elastic into that closes the notebook, which is necessary because with three inserts in it the notebook does not close completely without the elastic around it. The closure elastic is looped around one of the three elastics that run down the cover's spine. The elastic it is attached to slightly shifts when wrapping the closure elastic around the notebook. The elastic does not leave the spine's notches; it is only a minor aesthetic annoyance. I wonder if looping the closure elastic through a metal ring, punching a hole in the cover's spine and running the closure elastic from the inside to the outside would work, but worry about the ring squeezing the paper. For now I will leave it as it is.
I have been using the X17 with the Field Notes weekly calendar, a X17 grid insert for my todos and a Moleskine Volant, which is about twice as thick as standard pocket notebooks and X17 inserts, and could not be happier with it. I also wrapped the transparent slip pocket insert around the main paper block to hold my calendar open at the current week and fitted the bookmark band. The package is small for the amount of paper it holds, has a high-quality look and feel to it and provides the flexibility I want without adding much bulk.