Note 6 - Segment Information - Reportable Segments (Details) - USD ($)		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Net sales		$ 3,528,691	$ 4,071,478
Cost of goods sold		2,519,572	2,709,059
Gross profit (loss)		1,009,119	1,362,419
Selling general and adminstrative*		1,381,965	1,348,983
Research and development*		178,842	154,076
Income (loss) from operations		(551,688)	(140,640)
Trade receivables		1,821,114		$ 2,215,215
Segment Reconciling Items [Member]
Net sales		3,528,691	4,071,478
Cost of goods sold		2,519,572	2,709,059
Gross profit (loss)		1,009,119	1,362,419
Selling general and adminstrative*	[1]	1,381,965	1,348,983
Research and development*	[1]	178,842	154,076
Income (loss) from operations		(551,688)	(140,640)
Trade receivables		(74,872)		(43,147)
Chromaline [Member] | Operating Segments [Member]
Trade receivables		1,200,281		1,550,411
Ikonics Imaging [Member] | Operating Segments [Member]
Net sales		92,760	88,666
Cost of goods sold		34,046	25,392
Gross profit (loss)		58,714	63,274
Selling general and adminstrative*	[1]	34,605	34,852
Research and development*	[1]
Income (loss) from operations		24,109	28,422
Trade receivables		416,230		360,551
Domestic [Member] | Operating Segments [Member]
Net sales		2,029,341	2,340,810
Cost of goods sold		1,553,610	1,664,878
Gross profit (loss)		475,731	675,932
Selling general and adminstrative*	[1]	445,003	425,329
Research and development*	[1]
Income (loss) from operations		30,728	250,603
Export [Member] | Operating Segments [Member]
Net sales		1,088,806	1,219,348
Cost of goods sold		585,504	623,611
Gross profit (loss)		503,302	595,737
Selling general and adminstrative*	[1]	322,453	285,025
Research and development*	[1]
Income (loss) from operations		180,849	310,712
DTX [Member] | Operating Segments [Member]
Net sales		317,784	422,654
Cost of goods sold		346,412	395,178
Gross profit (loss)		(28,628)	27,476
Selling general and adminstrative*	[1]	88,148	84,783
Research and development*	[1]
Income (loss) from operations		(116,776)	(57,307)
Trade receivables		40,775		15,692
AMS [Member] | Operating Segments [Member]
Net sales
Cost of goods sold
Gross profit (loss)
Selling general and adminstrative*	[1]	491,756	518,994
Research and development*	[1]	178,842	154,076
Income (loss) from operations		(670,598)	$ (673,070)
Trade receivables		$ 238,700		$ 331,708

[1] The Company does not allocate all selling, general and administrative expenses or any research and development expenses to its operating segments for internal reporting.