Interleaved 2 of 5 (ITF) Barcode FAQ & Tutorial by IDAutomation®

Interleaved 2 of 5 (ITF, i2of5) is a numeric only barcode used to encode pairs of numbers into a self-checking, high-density barcode format. In this symbology, every two digits are interleaved with each other to create a single symbol. If a number string containing an odd number of digits needs to be encoded, a leading zero must be added to produce an even number of digits in the Interleaved 2 of 5 barcode. In many cases, the Code 128 barcode offers an advantage over the i2of5 barcode because it encodes even and odd numbers of digits, as well as letters and symbols, with equal or greater density.

The symbology of the character set consists of barcode symbols representing numeric characters 00 to 99, the space character and start/stop characters. The complete printed barcode consists of a leading quiet zone, a start pattern, interleaved symbols representing data, an optional MOD 10 check character, a stop pattern, a trailing quiet zone and an optional bearer bar pattern surrounding the entire symbol.

USS Interleaved 2 of 5 (Uniform Symbology Specification Interleaved 2 of 5) is the published specification for Interleaved 2 of 5. All IDAutomation products support the published specification. Several standards exist that dictate how ITF barcodes should be generated for certain implementations; a few of these include ITF-14, EAN-14, SCC-14, GTIN & DUN14.

Barcode example created with bearer bar fonts.

The purpose of "Bearer Bars" and the checksum is to reduce the possibility of misreads or short scans that may occur when a skewed scanning beam enters or exits the barcode symbol through its top or bottom edge. Bearer Bars should be a constant minimum thickness of twice the width of the narrow bar, placed directly against the top and bottom of the symbol bars. The bearer bars should completely surround the symbol, including the Quiet Zones, which are a minimum of 10 times the X dimension, which is the width of the narrow bar of the barcode. Many mandates for i2of5 require Bearer Bars and a MOD 10 Checksum.

Several Barcode Integration Guides are available that suggest one or more barcode printing options. These integration options should be examined to determine whether to use barcode components, applications or barcode fonts for the printing of Interleaved 2 of 5 barcodes. A few of the Barcode Integration Guides offered include the following:

The IDAutomation Universal Barcode Font is a unique product that excels at generating ITF barcodes on multiple operating systems and locales, including Double Byte versions of Windows. This product overcomes the obstacles that sometimes occur when printing the Interleaved 2of5 barcode font outside of the USA.

The most common method of reading barcodes is with a barcode scanner. Most of the barcode scanners recommended by IDAutomation perform keyboard emulation and receive power from the USB port, so that no external power supply is required. When a barcode is scanned using keyboard emulation, the data scanned appears at the cursor as if it had been typed in from the keyboard.

Most barcode scanners have the ability to read ITF barcodes by default, such as the IDAutomation USB Barcode Scanner. This scanner dependably reads the IDAutomation Universal Barcode Font when printed as small as 6 points, which is an X dimension of 4 mils.

IDAutomation provides several font tools, macros and source code samples that may be used royalty-free with IDAutomation barcode fonts, which automatically format the data being encoded to the barcode fonts. Therefore, references to this character set may not be necessary.

The "ITF Code" column lists the character that the scanner will read for the associated symbol. The columns ASCII, Char and Unicode designate the location in either ASCII or Unicode where the barcode symbol for the character resides in the barcode fonts.

The characters listed for values 94 and up are from the Latin-1 codepage. The "MAC" column lists unique ASCII codes for values 94 and up that may be used on the Macintosh in the Roman character set. When the Latin-1 or Roman codepages are not being used, it is suggested to use the Universal Barcode Font Advantage™, which creates the ITF barcode as a font in any codepage and operating system in the same way.

ITF Code	ASCII *	Unicode *	Char	MAC	ITF Code	ASCII *	Unicode *	Char	MAC
na	0032	0020	space	na	51	0084	0054	T	084
00	0033	0021	!	033	52	0085	0055	U	085
01	0034	0022	"	034	53	0086	0056	V	086
02	0035	0023	#	035	54	0087	0057	W	087
03	0036	0024	$	036	55	0088	0058	X	088
04	0037	0025	%	037	56	0089	0059	Y	089
05	0038	0026	&	038	57	0090	005A	Z	090
06	0039	0027	'	039	58	0091	005B	[	091
07	0040	0028	(	040	59	0092	005C	\	092
08	0041	0029	)	041	60	0093	005D	]	093
09	0042	002A	*	042	61	0094	005E	^	094
10	0043	002B	+	043	62	0095	005F	_	095
11	0044	002C	,	044	63	0096	0060	`	096
12	0045	002D	-	045	64	0097	0061	a	097
13	0046	002E	.	046	65	0098	0062	b	098
14	0047	002F	/	047	66	0099	0063	c	099
15	0048	0030	0	048	67	0100	0064	d	100
16	0049	0031	1	049	68	0101	0065	e	101
17	0050	0032	2	050	69	0102	0066	f	102
18	0051	0033	3	051	71	0103	0067	g	103
19	0052	0034	4	052	71	0104	0068	h	104
20	0053	0035	5	053	72	0105	0069	i	105
21	0054	0036	6	054	73	0106	006A	j	106
22	0055	0037	7	055	74	0107	006B	k	107
23	0056	0038	8	056	75	0108	006C	l	108
24	0057	0039	9	057	76	0109	006D	m	109
25	0058	003A	:	058	77	0110	006E	n	110
26	0059	003B	;	059	78	0111	006F	o	111
27	0060	003C	<	060	79	0112	0070	p	112
28	0061	003D	=	061	80	0113	0071	q	113
29	0062	003E	>	062	81	0114	0072	r	114
30	0063	003F	?	063	82	0115	0073	s	115
31	0064	0040	@	064	83	0116	0074	t	116
32	0065	0041	A	065	84	0117	0075	u	117
33	0066	0042	B	066	85	0118	0076	v	118
34	0067	0043	C	067	86	0119	0077	w	119
35	0068	0044	D	068	87	0120	0078	x	120
36	0069	0045	E	069	88	0121	0079	y	121
37	0070	0046	F	070	89	0122	007A	z	122
38	0071	0047	G	071	90	0123	007B	{	123
39	0072	0048	H	072	91	0124	007C	\|	124
40	0073	0049	I	073	92	0125	007D	}	125
41	0074	004A	J	074	93	0126	007E	~	126
42	0075	004B	K	075	94	0197	00C5	Å	136
43	0076	004C	L	076	95	0198	00C6	Æ	137
44	0077	004D	M	077	96	0199	00C7	Ç	138
45	0078	004E	N	078	97	0200	00C8	È	139
46	0079	004F	O	079	98	0201	00C9	É	140
47	0080	0050	P	080	99	0202	00CA	Ê	141
48	0081	0051	Q	081	START	0203	00CB	Ë	142
49	0082	0052	R	082	STOP	0204	00CC	Ì	143
50	0083	0053	S	083

* Some ASCII and Unicode values in this chart are unique to IDAutomation Interleaved 2 of 5 Barcode Fonts. The specification for Interleaved 2of5 does not specify the location of ASCII and Unicode values for the symbols in a font.

IDAutomation provides several font tools, plug-ins and source code samples that are free to use with IDAutomation barcode fonts, which will automatically format the start, stop and check characters to the barcode fonts. Therefore, the manual calculations described here are rarely necessary.

The following examples create a barcode with IDAutomation Interleaved 2 of 5 Barcode Fonts in the Latin-1 codepage, which is the default setting in the USA. When the Latin-1 codepage is not being used, or when using a Macintosh, it is suggested to use the Universal Barcode Font Advantage™, which creates i2of5 barcodes as a font in any codepage and operating system.

Since Interleaved 2 of 5 requires an even number of digits to “interleave” numbers, the data encoded must be an odd number of digits when using a check character, thus resulting in the required even number of digits.

The standard method of obtaining the check character (referred to as USS Interleaved 2 of 5 MOD 10) is obtained by performing the following calculation:

For example, the check digit for 123456789 is 5 because (3*(1+3+5+7+9))+(2+4+6+8) = 95 and 95 + 5 =100.

The calculation for Identcode and Leitcode applications is similar to USS Interleaved 2 of 5 MOD 10, except that even numbers are multiplied by 9 and odd numbers by 4. For example, the check digit for 12345678901 would be "6" because (4*(1+3+5+7+9+1))+(9*(2+4+6+8+0)=284 and 284 + 6 = 290.

Interleaved 2 of 5 Barcode (ITF) FAQ & Tutorial