A mum smuggled spice worth £7,000 into Armley Jail on a piece of paper containing a child's drawing.
Kate Morton hid the drawing - which had been soaked in the synthetic cannabis drug - inside her bra before going to meet her boyfriend at the prison in Leeds.
Morton, 37, was caught by prison staff after she was spotted taking the paper out and hiding it in a crisp packet in the visiting area.
Leeds Crown Court heard Morton travelled to West Yorkshire from her home in Swindon to visit her partner who was an inmate at the time of the incident, August 25, 2017.
Bashir Ahmed, prosecuting, said: "During the course of the visit she was seen to remove something from her bra, place it in a crisp packet and pass it to the inmate she was visiting.
"As the process was taking place she was taken to one side then removed from the visiting hall.
"She still had the crisp packet in her hand and dropped it when they went out of the hall."
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A folded piece of paper with coloured drawings on was found wrapped in clingfilm inside the crisp packet.
Mr Ahmed said the paper was found to have been impregnated with spice.
An expert who examined the paper said it could have been cut up into one centimetre squares to be sold for up to £5 each.
Morton was interviewed and said she had been put under pressure by her boyfriend to pick up the piece of paper from a woman before taking it to the prison.
Mr Ahmed said: "She was told that it was a drawing done by her boyfriend's nephew so he could stick it up on the wall of his cell."
Morton, of The Circle, Swindon, Wiltshire, pleaded guilty to conveying a List A article into prison.
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Mr Ahmed said Morton pleaded guilty to the offence on the basis that she was aware the paper contained an illicit substance but did not know what it was.
Morton's barrister, Aubrey Sampson, told yesterday's hearing that Morton's mother's funeral was due to take place today (Friday May 10).
Judge Tom Bayliss, QC, adjourned the hearing as "an act of mercy" so Morton could attend the funeral.
The mum-of-four will be sentenced on Thursday May 16.