As nouns the difference between backcloth and sackcloth
is that backcloth is the painted scenery at the back of a stage; the backdrop while sackcloth is a coarse hessian style of cloth used to make sacks.
backcloth
English
Noun
(
en noun)
the painted scenery at the back of a stage; the backdrop
sackcloth
English
Noun
(
en noun)
A coarse hessian style of cloth used to make sacks.
(Usually paired with 'ashes'), garments worn as an act of penance. Now often used figuratively.
- After he realised the gravity of his crime he spent some time wearing sackcloth and ashes.
References
* OED2