Written out
Every accidental is written in, rather than left to a key signature, so the letters can be read one at a time.
The step pattern
FW+HA♭WB♭HC♭HCW+HE♭WF
What is true of it
F blues is F, A♭, B♭, C♭, C and E♭, and back to F.
Its steps are W+H – W – H – H – W+H – W, where W is a whole step and H a half.
Across the first twelve frets of the ukulele its notes fall in 25 places, which is what makes a scale a shape rather than a list.
Chords made only of these notes
Found by testing every chord in the catalogue against these 6 sounds, not chosen.
Other scales on F
F major pentatonicpentatonicF minor pentatonicpentatonicF major bluespentatonicF majormajorF natural minorminorF harmonic minorminor
C bluesC♯ bluesD♭ bluesD bluesD♯ bluesE♭ bluesE bluesF♯ bluesall 374