INVENTORIES (Details) - USD ($)	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018
INVENTORIES
Finished goods	$ 6,419,000	$ 5,448,000
Work in process	1,061,000	1,365,000
Raw materials and supplies	6,473,000	7,993,000
Inventories	13,953,000	14,806,000
Increase in inventories, if inventories valued on the LIFO basis were valued at current costs	6,618,000	7,176,000
Decrease in net loss due to inventory adjustment	(968,000)
Inventory valuation reserves	$ 1,023,000	$ 1,747,000