I have a font named "Anastasia" on my computer that includes two pairs of blank guitar fret diagram grids. I don't know where that font came from but suspect it was included with one of my several notation programs. If it's not on your machine, you might be able to find it by searching the web(?), although without a known source the same name often appears on fonts with different character sets.

In my Anastasia, Hex character number 008E has a heavier bar at the top indicating the nut, so would be useful only for "1st position" chords, but hex char 008F has all the horizontals the same weight. You'd number the top one to show what fret it locates on (or where to put the capo).

A peculiarity of the Anastasia font is that when you type an E or F in Word with that font set it immediately changes to something else. Thus you can't enter those glyphs by typing the Hex char number with Anastasia set as the font. You can, in Word, use the decimal equivalents with the Alt-Numpad method to insert them, using 0142 for the one with the nut and 0143 for the one without.

Since Anastasia is a "non-text" font, it may not show in Word's font selection box even if it's properly placed in C:\Windows\Fonts, so you may have to type the name there, with the characters you want to format selected, and hit enter. If the font is in C:\Windows\Fonts Word will use it, even though it doesn't show in the font selection box.

Character Map shows an identical pair in Anastasia at 488E and 488F, but since I have a real (Unicode compliant) font with those character numbers, and those numbers are outside the range used by Office font pages, I haven't figured out how to get them to display the Anastasia glyphs since it "reverts" to the Chinese font that Unicode assigns the numbers to.

Since you may not be able to find the same Anastasia that I have, the "how to" of getting it into Word is mostly to suggest that you may encounter similar difficulties with any font you find that has the character picture you want, since the available fonts will have the pictures translated to numbers normally assigned to other glyphs. Windows Character Map will tell you what the Hex Character Numbers are for any character in the font, but for numbers that convert to decimal values with four or fewer digits the Alt-NumPad method may work better.

Unicode assigns the hex character number 1D11C (decimal 119053) to an empty 6-string fretboard and 1D11D (decimal 119054) to a four string one, but no common font that I know of includes characters in that range (above about Hex FFFE = Decimal 65534).

The FretsA, FretsB, and FretsC that likely are the most common ones used for fret diagrams in notation programs do not include a blank fret box in the versions I have - which is somewhat surprising.

Simplify:

Draw the diagram you want. Scan to jpg. Scale as desired. Make a sheet with a dozen or two of them on it and print. Cut and paste onto music pages as needed. Make a copy if you're afraid the paste won't hold it together.

Or take the picture in and have a rubber stamp made.

John