ITF | Interleaved 2 of 5 | ITF-14 Barcode FAQ

ITF-14
Bearer Bar and Checksum Options
Printing Interleaved 2 of 5
The Barcode Font Character Set
Reading & Scanning
Check Character Calculation Examples
FAQ

Overview

Interleaved 2 of 5 (ITF) 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 barcodes. In many cases, the Code 128 barcode offers an advantage over the ITF barcode because it encodes even and odd numbers of digits, as well as letters and symbols, with nearly equal 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.

The IDAutomation Interleaved 2 of 5 Barcode Font Package provides 4 different font formats (as shown in the graphic to the right) to meet various requirements. These formats are, in the order they appear:

Standard
Standard Human Readable
Bearer Bar
Bearer Bar Human Readable
Bearer Bar Human Readable with Vertical Bearer Bars Excluded (not shown)

The bearer bar versions are provided to meet certain specifications, such as GS1 ITF-14. Some of these specifications state that only horizontal bearer bars along the top and bottom of the barcode symbol are necessary; the bearer bar versions provided in this package surround the barcode, which meet or exceed any bearer bar requirement.

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, VCA OPC, and DUN14.

ITF-14

ITF-14 is the GS1 System’s only use of Interleaved 2 of 5, and it is only used to encode the GTIN as a 14-digit number. It is commonly used on shipping boxes and is usually printed directly on the cardboard box. This implementation usually uses bearer bars to help eliminate read errors.

Bar Height:
The minimum recommended bar height for an ITF-14 Barcode is 32mm (1.25″) when used in General Distribution Scanning environments (automated scanning). For all other scanning applications, the height should be as high as possible. In no case shall the bar height be less than 13mm (.5″). While 13mm (.5″) is the minimum height for barcodes not being scanned in an automated scanning environment, every effort should be made to increase the bar height to 32mm (1.25″) as much as possible.

Bar Width (X Dimension):
The X Dimension is the width of the smallest bar in the symbol. In automated scanning environments, the X Dimension should be 0.495mm – 1.02mm (20 to 40mils). For all other scanning applications, the acceptable range is 0.250mm to 0.495mm (10-20mils).

Bar Width Ratio (N Dimension):
The bar width ratio (also known as the Narrow to Wide ratio or the N Dimension) is the difference in bar widths between the wide bars and the narrow bars in an ITF-14 Barcode. The acceptable range is 2.25:1 to 3:1. The IDAutomation Interleaved 2 of 5 Barcode Fonts have an N dimension of 2.75:1.

When using the IDAutomation Interleaved 2 of 5 Barcode Fonts, the following chart provides the recommended font name and size to use.

Environment	Font Name	Point Size	X Dimension	Height
Automated Scanning	IDAutomationI25XL	28	.495mm (20 mils)	38mm (1.5″)
General Scanning	IDAutomationI25L	14	.25mm (10 mils)	14mm (.55″)

Bearer Bar and Checksum Options

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 have 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 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. Some specifications state that only horizontal bearer bars along the top and bottom are necessary; however, it is better to use bearer bars that surround the barcode because they meet or exceed any bearer bar requirement.

IDAutomation provides several sets of ITF bearer bar fonts (which surround the barcode) in the Interleaved 2 of 5 Barcode Fonts. In addition, IDAutomation provides many Font Encoders, Components, and Applications that easily support Bearer Bars and checksum calculations.

Printing ITF Barcodes

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:

Featured Product:

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. It also provides three different narrow-to-wide ratios: 2, 2.5, and 3.

Reading & Scanning

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 can 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.

The ITF Barcode Font Character Set

The character set referenced here is unique to the IDAutomation Interleaved 2 of 5 Barcode Font. IDAutomation provides several font encoders, macros, and source code samples that may be used royalty-free with this font to automatically format the data being encoded to the barcode fonts. Therefore, references to this character set may not be necessary.

To manually create a barcode encoding the number 772233 with the chart below, use the following process:

Include the START character: Ë
Include the data characters from the Char columns that represent 2 numbers from the ITF code column. For example, the numbers 77 22 33 are represented in characters: n7B
Include the STOP character: Ì
Combine the resulting text string with the barcode font: Ën7BÌ

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. When the Latin-1 codepage is 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 Barcode Character Set Chart

ITF Code	ASCII *	Unicode *	Char	ITF Code	ASCII *	Unicode *	Char
na	0032	0020	space	51	0084	0054	T
00	0033	0021	!	52	0085	0055	U
01	0034	0022	“	53	0086	0056	V
02	0035	0023	#	54	0087	0057	W
03	0036	0024	$	55	0088	0058	X
04	0037	0025	%	56	0089	0059	Y
05	0038	0026	&	57	0090	005A	Z
06	0039	0027	‘	58	0091	005B	[
07	0040	0028	(	59	0092	005C	\
08	0041	0029	)	60	0093	005D	]
09	0042	002A	*	61	0094	005E	^
10	0043	002B	+	62	0095	005F	_
11	0044	002C	,	63	0096	0060	`
12	0045	002D	–	64	0097	0061	a
13	0046	002E	.	65	0098	0062	b
14	0047	002F	/	66	0099	0063	c
15	0048	0030	0	67	0100	0064	d
16	0049	0031	1	68	0101	0065	e
17	0050	0032	2	69	0102	0066	f
18	0051	0033	3	70	0103	0067	g
19	0052	0034	4	71	0104	0068	h
20	0053	0035	5	72	0105	0069	i
21	0054	0036	6	73	0106	006A	j
22	0055	0037	7	74	0107	006B	k
23	0056	0038	8	75	0108	006C	l
24	0057	0039	9	76	0109	006D	m
25	0058	003A	:	77	0110	006E	n
26	0059	003B	;	78	0111	006F	o
27	0060	003C	<	79	0112	0070	p
28	0061	003D	=	80	0113	0071	q
29	0062	003E	>	81	0114	0072	r
30	0063	003F	?	82	0115	0073	s
31	0064	0040	@	83	0116	0074	t
32	0065	0041	A	84	0117	0075	u
33	0066	0042	B	85	0118	0076	v
34	0067	0043	C	86	0119	0077	w
35	0068	0044	D	87	0120	0078	x
36	0069	0045	E	88	0121	0079	y
37	0070	0046	F	89	0122	007A	z
38	0071	0047	G	90	0123	007B	{
39	0072	0048	H	91	0124	007C	\|
40	0073	0049	I	92	0125	007D	}
41	0074	004A	J	93	0126	007E	~
42	0075	004B	K	94	0197	00C5	Å
43	0076	004C	L	95	0198	00C6	Æ
44	0077	004D	M	96	0199	00C7	Ç
45	0078	004E	N	97	0200	00C8	È
46	0079	004F	O	98	0201	00C9	É
47	0080	0050	P	99	0202	00CA	Ê
48	0081	0051	Q	START	0203	00CB	Ë
49	0082	0052	R	STOP	0204	00CC	Ì
50	0083	0053	S

* 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 actual location of ASCII and Unicode values for the symbols in a font.

MOD 10 Check Character Calculation Examples

MOD10 check digits may be verified with the free Barcode Data Decoder App, which scans the barcode and highlights the check digit in green when the calculation is correct.

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

Generating Standard MOD 10 Check Digits:

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:

Add up the odd numbers in the code.
Multiply the sum of the odd numbers in the code by 3.
Add up the even numbers.
Determine the number that, when added to the sum, will produce a multiple of 10.

For example, the check digit for 123456789 is 5 because (3*(1+3+5+7+9))+(2+4+6+8) = 95. The next multiple of 10 after 95 is 100; therefore, the check digit would be 5, because 95 + 5 =100.

Identcode & Leitcode Checksum Calculations:

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.

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 Mac, it is suggested to use the Universal Barcode Font, which creates ITF and many other barcode types from a single font in any codepage and operating system.

Frequently Asked Questions (FAQ)

What is Interleaved 2 of 5 (ITF)?

Interleaved 2 of 5 is a high-density, numeric-only barcode symbology that encodes data in pairs of digits (each symbol representing two numbers) and is commonly used for applications such as shipping cartons and logistic labels. For a detailed tutorial, see the BarcodeFAQ Interleaved 2 of 5 guide.

How is Interleaved 2 of 5 different from other 1-D barcodes?

Unlike barcodes that encode one character per symbol, Interleaved 2 of 5 encodes two numeric digits in one symbol by interleaving bars and spaces, which increases density. If your data includes letters or odd number of digits, another symbology may be more appropriate. More on this difference is available at BarcodeFAQ.

What do I need to generate an Interleaved 2 of 5 barcode?

To generate an Interleaved 2 of 5 barcode you’ll need data formatted correctly (an even number of digits unless a check digit is used), a generator or font that supports the ITF specification, and optionally an encoder to automate formatting. For example, the IDAutomation Interleaved 2 of 5 Barcode Font Package supports multiple formats, and the IDAutomation Font Encoders make automation easier.

When should I use Interleaved 2 of 5 instead of other symbologies?

Use Interleaved 2 of 5 when you have numeric data that needs high density in a barcode, particularly for logistics, carton labels, or GS1 ITF-14 applications (such as encoding a 14-digit GTIN on a shipping box). If you also need letters, variable data length, or omnidirectional scanning, consider other barcodes. See the BarcodeFAQ overview.

What are the key technical considerations (check digits, bearer bars, X-dimension)?

When using Interleaved 2 of 5:
– The data should usually be an even number of digits; if odd, prepend a zero or add a check digit.
– Many applications (like GS1 ITF-14) require a MOD 10 check digit.
– Bearer bars (horizontal or full-frame) are sometimes required for carton scanning to prevent misreads.
– The X-dimension (width of the narrow bar) and the narrow-to-wide (N) ratio must meet the specification (for example 2.25:1 to 3:1).
For more detailed specs, refer back to the BarcodeFAQ ITF page.