Akademik

Л-155
HE ВСЙКО(Е) ЛЫКО В СТРОКУ (saying) not every error or fault should be held against the person who committed it (said to excuse a person who has made a blunder also said as advice not to carp on trivial matters): — don't quibble over every trifle everybody makes mistakes.
In old Russia, strips («строки») of bast («лыко») were used to make woven sandals. Not all bast was of good enough quality for use as strips.

Большой русско-английский фразеологический словарь. — М.: ACT-ПРЕСС КНИГА. . 2004.