Printers that make three-dimensional metal objects already exist, but HP said Metal Jet can produce a lot more parts at "significantly" lower cost than existing machines.
The dip in manufacturing payrolls in August breaks an almost yearlong streak of solid gains.
Canadian Foreign Minister Chrystia Freeland has said there’s progress, but that no deal is done until it’s done.
The report adds to signals that the nearly decade-old expansion will hold up well in the second half of 2018.
Negotiations resume between the U.S. and Canada on Wednesday.
Manufacturing production also rose at the slowest pace in 17 months, while both input and output prices increased.
Economists see government stimulus measures aiding sentiment.
Canada's foreign minister sees spirit of compromise but ‘huge’ workload remains.