Alphabest — a heterogrammatical word grid challenge

What is a heterogram? It's a word that contains all different letters, like productively and absurdity and formidably. How many heterograms of 9 or more letters can you find?

Our friend, the Honest Poet, told us of two simultaneous words—blacksmith and gunpowdery—whose 20 different letters leave just six unused! These two words are also called isograms, because both words are the same length. Then he added his own pair, lumberjack and downshift, using up 19 letters. Impressive. Our sample below uses all 26 letters by interweaving 7 words.

Your challenge with Alphabest is to form a crossword puzzle arrangement that uses all 26 letters exactly once. The 7 words in the sample above, solved by Eric Bare, fit into a 9x9 grid, a total of 81 squares. Can you do better with a smaller grid? Send us your own solutions and win a prize. And don't worry, they're uncopyrightable. (See? "Uncopyrightable" is also a heterogram.)

If you have a Scrabble® set, just use one of each of the 26 different letters. Or use a set of Mini-Mouth® from ThinkFun that contains exactly one alphabet. Then you can lay out your project and move letters around till you find the best result. No abbreviations, no proper nouns or foreign words are allowed. Check a standard dictionary, printed or online, to verify spellings. Have fun puzzling with matchless words!

New solutions
Ken Futamura has improved on our first results with a 9x8 (72) and a 10x7 (70) grid:

Ronald Park constructed an even tighter fit, 15x4 (60) tweaked by George Sicherman:

Here's an even more compact 9x6 (54) solution by George Sicherman:

Ken Futamura rose to the challenge and outdid the previous best 15x4 by one whole row to 15x3 (45), assuring us that all the words are allowed by Scrabble:

It's hard to imagine a more condensed solution, so congratulations to all three of you gentlemen for these alphabest bests!

On April 2, 2018, German Gonzalez-Morris amazed us with a new world record for Alphabest with this 14x3 (42) solution, and all those words are indeed in the dictionary. Congratulations, champ!