A free standing magnetic blocks will have 18" of surface. I won't make it longer as it probably will look a bit unwieldy in a larger size. The tip-down design never appealed to me for a number of reasons. One, you got to twist your wrist (thumb down position) to get your hand on the handle of a knife. Awkward at best. Two, some will store the block on a counter-top under the cabinet, and clearance will vary, so imagine that you bump into the bottom of the cabinet every time trying to get your hand on the knife handle. Add the awkwardly twisting your hand while doing this, and perhaps you will see why I never considered this to be a good design. It's pretty amazing to me that many of designs for blocks out there are of this kind - but hey, here is an opportunity to be different.
The board will be taller than the tallest knife, so your tips will never be exposed. In fact it will have a similar to Henckels rest for handles, so knives will be lined up at the bottom.
Cleaning and buffing it will be a breeze. I can use different strength magnets, however this is not as important, as the block will be slanted, and knives will be rested on a board (gravity), and only light magnetic pull will be required to keep them in place.
Nothing is written in stone and the design will be up for revision if necessary,
M