Eamonn O'Donnell, 39, a mature student, was sentenced to 20 years and his colleague, Sean Cruickshank, 23, a lorry driver, was jailed for 15 years by a judge at Newcastle Crown Court.
Their campaign one night last June caused more than pounds 50,000 damage in Leeds when they planted nine incendiary devices in city centre stores. Five premises were targeted but only four devices went off.
In the worst incident, the Stop And Shop store was gutted by explosives packed inside an audio cassette case. The court was told that O'Donnell and Cruickshank were seen earlier in the day planting two devices in the furnishing department of a branch of Marks & Spencer.
After the shop was evacuated a bomb disposal team made safe the cassettes, which were packed with capsules of lighter fuel. The men were recorded on the store's security surveillance cameras and their high-resolution pictures were distributed around England.
A detective at Leeds-Bradford Airport recognised O'Donnell and he was arrested near his lodgings at Bradford and Ilkley College, where he was on a community and social welfare studies. Weeks later, Cruickshank was arrested by police at the ferry terminal in Stranraer, Scotland. They admitted conspiracy to cause arson.
Mr Justice Macpherson told them: 'Good detective work by the police had you well and truly nailed for these cowardly crimes against the citizens of Leeds.'
He added: 'Your principal aim was damage to property, but I will not blind myself to the risk to nightwatchmen, firefighters, bomb disposal soldiers, shop staff and the public generally.'