Nearly 3,000 jobs are to be axed after the administrators of Clinton Cards announced plans to close 350 stores.
All of the group's Birthdays stores and roughly 200 Clintons-branded stores will close after administrators said the business was "burdened with an untenable retail estate".
The move will see 2,800 full and part-time staff lose their jobs in a wave of store closures starting next week and continuing into June.
The ailing high street retailer, which had 784 stores and employed more than 8,000 staff in total, collapsed into administration last week after its biggest supplier American Greetings called in a £35 million debt.
Peter Saville, joint-administrator Zolfo Cooper, said: "Given the sheer size of the Clinton Cards retail estate and the overall performance, we were left with no alternative to today's difficult decision.
"I am hopeful that the action we have taken will allow us to preserve value in the core underlying business, thereby allowing us and potential buyers to focus on a profitable and viable retail estate going forward."
There have recently been reports that WHSmith, which bought the online personalised greetings card brand Funky Pigeon in 2010, is interested in buying up to 350 stores.
And Card Factory, Clinton's biggest competitor with 596 stores, is also thought to have approached administrators.
Clinton has suffered dire trading in recent months as it comes up against stiff competition from supermarkets and online retailers such as Funky Pigeon and Moonpig.
It recorded a pre-tax loss of £3.7 million in the 26 weeks to January 29, compared with a profit of £11.7 million in the previous year, and warned that the second half of the year would be below expectations. Its shares had lost more than 80% of their value since the start of 2010.