CD and CDL strings are characterised by a high standardised specific weight achieved by metallic copper powder deposition during extrusion (no mercury or lead salts are used). The dull surface is similar to polished natural gut. The sound is powerful and warm, with short sustain, without the excessive brilliance typical of modern wound strings, blending perfectly with the higher tuned strings.
CAUTION! For single-string use (with high tension) on theorbos/chitarrones, CD strings are only recommended from the 6th course onwards. For the 5th course CDL strings should be used, otherwise there is a risk of breaking!
The correct stringing of these strings (n. M. Peruffo):
Both the CD and CDL strings are made of a synthetic elastomer, which is characterised by the fact that it does not slide (this is why elastomers are also used for the soles of shoes). This means that the usual method of stringing does not work as expected and can lead to unexpected string breakage: In fact, the poor glide of the material leads to higher tension in the area between peg and nut compared to the tension between nut and bridge.
The CD type is in itself very resistant: just as an example, a 145CD string will not break until a linear tension of 12 kg is applied.
The correct procedure is that once the string is attached to the peg, it must be kept out of the nut of the saddle at all times during the initial tuning process and only placed in the nut when it has been pulled by the hands and tuned to the desired tone.
In this way, the tension between the peg and the nut is the same as that between the nut and the bridge, which ensures high tuning stability and resistance to breakage.
The use of lubricants such as graphite in the grooves of the saddle has not proved to be a significant Advantage.