John Doe writes:

They still need lots of exercise using their claws. If you just stop them
with the tape, they will need to get that exercise some other way. Don't
just treat the symptom.

It's worth experimenting to see what kinds of things they like to
scratch. For instance, with our current cat, I'd nearly given up hope of
stopping him from scratching the back corner of the sofa[1], but I've
finally found that vertical or semi-vertical boards with jute fabric on
them are what really appeals in his case. Try varying material, shape
(flat, round, whatever), orientation, until you find an effective
sacrificial attractor. John's right, pieces of unfinished lumber can be
great too.

[1] discount from a charity shop at least, with children and cats it's
not worth paying any more than that!

-- Mark