Paper probes drunkard with problem, which is yielding material (4,6)

'yielding material' is the definition.
(I know that soft tissue is a subclass of yielding material)

'paper probes drunkard with problem' is the wordplay.
'paper' becomes 'FT' (newspaper the FT, Financial Times).
'probes' is an insertion indicator (probe can mean to poke or prod into).
'drunkard' becomes 'sot' (sot can mean a drunken person).
'with' is a charade indicator (letters next to each other).
'problem' becomes 'issue' (issue can mean a problem or difficulty).
'ft' put into 'sot' is 'softt'.
'softt'+'issue'='SOFT TISSUE'

'which is' acts as a link.