Green’s Dictionary of Slang

receive the canvas v.

[play on get the sack under sack n., which was often made of canvas; but note this significantly predates]

to be dismissed from a job.

[Ire] J. Shirley Brothers in Dramatic Works (1833) 207: And now I’ll tell thee, I have promis’d him As much as marriage comes to, and I lose My honour, if my don receive the canvas1 [...] [note] The phrase is taken from the practice of journeymen mechanics [...] When they are discharged by their masters , they are said to receive the canvas, or the bag; because in this, their tools and necessaries are packed up.