Art Zone owner Andrew Cook said intruders tied a canvas strap to a pole on the roof of a multi-storey building in Hanover St on Saturday night or Sunday morning.
They used the strap - the type used to tie down a load on a trailer - to lower themselves through a smashed skylight.
From the skylight, the intruders entered the University of Otago Department of Preventive and Social Medicine on the building's first floor.
Cabinets in the department were searched and a toner cartridge from a photocopier was emptied on a wall.
They went down a flight of stairs, leaving a trail of toner, into a hall on the ground level behind his art supply shop Art Zone.
In the shop, someone tried to ``jimmy open'' the cash register but failed, he said.
The burglars stole about 70 cans of Montana Gold spray paint, mostly shades of blue and some black and white.
Also stolen were about 40 ``big and fat'' water-based paint markers.
Shoplifters regularly targeted the markers, so the burglary had spurred a decision yesterday not to stock the product again.
However, the stolen spray paint would be restocked.
``I would dump it tomorrow if it wasn't such a good seller.''
It appeared the burglars left the shop in a rush and could have been spooked, he said.
Some went through a rear door to the car park, while others stacked desks to exit through the skylight, he said.
Art Zone was the only shop in Dunedin stocking the spray paint, which was packaged in distinctive gold cans, he said.
The burglary was the ``last thing'' the small business needed, Mr Cook said.
``We have a huge shoplifting problem at Art Zone and we have caught [past] staff stealing products and cash from the till and now the burglary.''
The company did not insure its stock because the excess was too expensive, he said.
``We have to pay for the losses out of our own pocket.''
A university spokeswoman said the university could not confirm if anything was stolen from the department.
Senior Sergeant Ben Butterfield, of Dunedin, said police wanted to hear from anyone who had seen anyone with the distinctive acrylic spray paint.
Dunedin police (03)471-4800, Crimestoppers 0800555-111.
