ITF-14 and Interleaved 2 of 5 (I-2/5) are workhorse linear symbologies for cartons, pallets, and inner logistics. ITF-14 encodes a GTIN-14 (14 digits, including a Mod-10 check digit) and is commonly printed with bearer bars on corrugated cardboard. I-2/5 is a compact, numeric-only, even-length symbology often used for internal trays and cases.

Complete Example ( Copy-Paste Ready)

What you get:

  • One .NET console app that can output ITF-14 and I-2/5 barcodes.
  • A GTIN-14 check digit helper for ITF-14.
  • Even-length enforcement for I-2/5.
  • Sensible defaults for print (margins, bar thickness, height).
  • PNG output by filename.

1) Create the project and add the package

dotnet new console -n ItfAndI25Demo -f net8.0
cd ItfAndI25Demo
dotnet add package Aspose.BarCode

2) Replace Program.cs with the following

using System;
using Aspose.BarCode.Generation;

namespace ItfAndI25Demo
{
    class Program
    {
        // Usage:
        // ITF-14  -> dotnet run -- itf14  400638133393  260930
        //            (first arg "itf14", second is GTIN base ≤13 digits; we'll compute the 14th check digit)
        // I-2/5   -> dotnet run -- i25   123456789
        //
        // Output files:
        //   ITF14_<gtin14>.png
        //   I25_<dataEven>.png

        static int Main(string[] args)
        {
            if (args.Length < 2)
            {
                Console.WriteLine("Usage:");
                Console.WriteLine("  ITF-14: dotnet run -- itf14 <gtin_base_≤13_digits> [xPixels=3] [heightMM=22] [marginMM=4]");
                Console.WriteLine("  I-2/5 : dotnet run -- i25   <numeric_data>        [xPixels=3] [heightMM=22] [marginMM=4]");
                return 1;
            }

            var mode = args[0].Trim().ToLowerInvariant();
            int xPixels = args.Length > 2 && int.TryParse(args[2], out var x) ? Math.Max(1, x) : 3;
            float heightMM = args.Length > 3 && float.TryParse(args[3], out var h) ? Math.Max(10f, h) : 22f;
            float marginMM = args.Length > 4 && float.TryParse(args[4], out var m) ? Math.Max(1f, m) : 4f;

            try
            {
                switch (mode)
                {
                    case "itf14":
                        {
                            string gtinBase = args[1].Trim();
                            if (gtinBase.Length > 13 || !IsAllDigits(gtinBase))
                                throw new ArgumentException("For ITF-14, provide a numeric GTIN base (≤13 digits). The 14th check digit will be computed.");

                            // Build full GTIN-14: left-pad to 13 digits, then add Mod-10 check digit
                            string gtin13 = gtinBase.PadLeft(13, '0');
                            char check = CalcGtin14CheckDigit(gtin13);
                            string gtin14 = gtin13 + check;

                            // ITF-14 encodes the 14-digit GTIN
                            using var gen = new BarCodeGenerator(EncodeTypes.ITF14, gtin14);

                            // Print-friendly defaults
                            gen.Parameters.Barcode.XDimension.Pixels = xPixels;  // bar/module thickness
                            gen.Parameters.Barcode.BarHeight.Millimeters = heightMM;
                            gen.Parameters.Barcode.LeftMargin.Millimeters = marginMM;
                            gen.Parameters.Barcode.RightMargin.Millimeters = marginMM;
                            gen.Parameters.Barcode.TopMargin.Millimeters = Math.Max(2f, marginMM / 2f);
                            gen.Parameters.Barcode.BottomMargin.Millimeters = Math.Max(2f, marginMM / 2f);

                            // Optional: show human-readable text below (depends on layout preference)
                            gen.Parameters.Barcode.CodeTextParameters.Location = CodeLocation.Below;
                            gen.Parameters.Barcode.CodeTextParameters.FontSize.Point = 8f;

                            // Save PNG (lossless)
                            string file = $"ITF14_{gtin14}.png";
                            gen.Save(file, BarCodeImageFormat.Png);

                            Console.WriteLine($"✅ ITF-14 saved: {file}");
                            break;
                        }
                    case "i25":
                    case "interleaved2of5":
                    case "interleaved_2_of_5":
                        {
                            string data = args[1].Trim();
                            if (!IsAllDigits(data))
                                throw new ArgumentException("I-2/5 requires numeric data.");

                            // I-2/5 needs an even number of digits; if odd, left-pad with '0'
                            string evenData = data.Length % 2 == 0 ? data : "0" + data;

                            using var gen = new BarCodeGenerator(EncodeTypes.Interleaved2of5, evenData);

                            // Print-friendly defaults
                            gen.Parameters.Barcode.XDimension.Pixels = xPixels;
                            gen.Parameters.Barcode.BarHeight.Millimeters = heightMM;
                            gen.Parameters.Barcode.LeftMargin.Millimeters = marginMM;
                            gen.Parameters.Barcode.RightMargin.Millimeters = marginMM;
                            gen.Parameters.Barcode.TopMargin.Millimeters = Math.Max(2f, marginMM / 2f);
                            gen.Parameters.Barcode.BottomMargin.Millimeters = Math.Max(2f, marginMM / 2f);

                            gen.Parameters.Barcode.CodeTextParameters.Location = CodeLocation.Below;
                            gen.Parameters.Barcode.CodeTextParameters.FontSize.Point = 8f;

                            string file = $"I25_{evenData}.png";
                            gen.Save(file, BarCodeImageFormat.Png);

                            Console.WriteLine($"✅ Interleaved 2 of 5 saved: {file}");
                            break;
                        }
                    default:
                        throw new ArgumentException("First argument must be 'itf14' or 'i25'.");
                }

                return 0;
            }
            catch (Exception ex)
            {
                Console.Error.WriteLine("❌ Error: " + ex.Message);
                return 2;
            }
        }

        // ----------------- Helpers -----------------

        // GTIN-14 check digit (Mod-10). Argument must be the first 13 digits as a string.
        static char CalcGtin14CheckDigit(string first13)
        {
            if (first13 is null || first13.Length != 13 || !IsAllDigits(first13))
                throw new ArgumentException("CalcGtin14CheckDigit expects 13 numeric digits.");

            int sum = 0;
            // Rightmost (position 13) is index 12; multiply alternating by 3 and 1, starting with 3 on the right.
            // From the rightmost toward left: 3,1,3,1,...
            for (int i = 0; i < 13; i++)
            {
                int digit = first13[12 - i] - '0';
                int weight = (i % 2 == 0) ? 3 : 1;
                sum += digit * weight;
            }
            int mod = sum % 10;
            int check = (10 - mod) % 10;
            return (char)('0' + check);
        }

        static bool IsAllDigits(string s)
        {
            if (string.IsNullOrEmpty(s)) return false;
            foreach (char c in s)
                if (c < '0' || c > '9') return false;
            return true;
        }
    }
}

3) Run a few examples

# ITF-14: pass ≤13 digits, we compute the 14th check digit
dotnet run -- itf14 400638133393
# -> ITF14_0400638133393X.png (X = computed check digit)

# Interleaved 2 of 5: any numeric string; we pad a leading 0 if odd length
dotnet run -- i25 123456789
# -> I25_0123456789.png

Step-by-Step (What the code is doing)

ITF-14 essentials

  • Encodes a GTIN-14 (14 digits total).
  • The last digit is a Mod-10 check digit.
  • Often printed large with quiet zones and sometimes bearer bars (a frame around the code) on corrugated.

In the code: we accept up to 13 digits, pad left to 13, compute the 14th, and pass all 14 digits to EncodeTypes.ITF14.

string gtin13 = gtinBase.PadLeft(13, '0');
char check = CalcGtin14CheckDigit(gtin13);
string gtin14 = gtin13 + check;
using var gen = new BarCodeGenerator(EncodeTypes.ITF14, gtin14);

Interleaved 2 of 5 essentials

  • Compact, numeric-only symbology.
  • Requires an even number of digits (pairs are interleaved).
  • We left-pad with 0 if the input is odd-length.
string evenData = data.Length % 2 == 0 ? data : "0" + data;
using var gen = new BarCodeGenerator(EncodeTypes.Interleaved2of5, evenData);
  • X-dimension (bar/module thickness): 3 px is a practical starting point for thermal printers.
  • Bar height: ~22 mm works well on 1×3″ or 2×1″ labels; adjust for your stock.
  • Quiet zones: ~4 mm left/right; 2–3 mm top/bottom.
  • Human-readable text: show below (CodeLocation.Below) if your label needs text.
gen.Parameters.Barcode.XDimension.Pixels = 3;
gen.Parameters.Barcode.BarHeight.Millimeters = 22f;
gen.Parameters.Barcode.LeftMargin.Millimeters = 4f;
gen.Parameters.Barcode.RightMargin.Millimeters = 4f;
gen.Parameters.Barcode.TopMargin.Millimeters = 2f;
gen.Parameters.Barcode.BottomMargin.Millimeters = 2f;
gen.Parameters.Barcode.CodeTextParameters.Location = CodeLocation.Below;
gen.Parameters.Barcode.CodeTextParameters.FontSize.Point = 8f;

Customization Ideas

  • Bigger labels / rough media → increase XDimension to 4–5 px.

  • Tighter labels → reduce bar height (18–20 mm) but never starve quiet zones.

  • Suppress HRT (human-readable text) if your layout prints text elsewhere:

    gen.Parameters.Barcode.CodeTextParameters.Location = CodeLocation.None;

Note on bearer bars (ITF-14): Many printers/standards prefer a frame or top/bottom bars around ITF-14 to prevent short scans. If your Aspose.BarCode build exposes specific ITF bearer bar parameters, enable them; otherwise, add the frame in your label layout.

Troubleshooting

  • Won’t scan on corrugated: Increase XDimension, ensure high contrast, add/confirm quiet zones, consider bearer bars.
  • I-2/5 rejected as odd length: You forgot to pad; use the code’s evenData logic.
  • ITF-14 check digit wrong: Ensure you pass only the first 13 digits to the calculator; let the code compute the 14th.

Best Practices

  • Lock parameters (X-dimension, height, margins) in config so output is reproducible.
  • Verify on your target scanners and label media—tweak by small increments.
  • Version your templates if you add logos/text above or below bars.
  • Keep it numeric: I-2/5 doesn’t support non-digits; sanitize inputs early.

Conclusion

With a few lines of code, you can produce robust, scanner-friendly ITF-14 and Interleaved 2 of 5 barcodes in .NET using Aspose.BarCode. Start with the complete example above, then tune bar thickness, height, and margins to your printers and scanners. The check-digit and even-length helpers make your data standards-safe from the start.

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