Above the gauge of 2mm gut and nylon strings do not produce a clear sound on folk harps, because they are too short, so it is advantageous to have strings metal wound on silk. These strings should be gauged as follows: .

String number	String notation	Diameter millimetres
28	B	1.30
29	A	1.40
30	G	1.50
31	F	1.60
32	E	1.70
33	D	1.80
34	C	2.00

The Paraguayan harp has 36 strings, and the two additional strings are at the top, so they are B and C. The gauge of these strings is 0.55 for the B and 0.50 for the top C.

All C strings (Doh) are coloured red; all F strings (Fah) are coloured blue or black; other strings are colourless. Metal strings are silver, except for C and F which are bronze. Octaves are counted from F strings, so that on the Celtic harp), for instance, the first octave will be No. 1 -A, No. 2-G and No. 3-F. The second octave will start at No. 4-E down to No. 10-F.