[TestMethod]
public void ZipTestMethod()
{
    StringBuilder builder;
    string lote, producto, fecha;
    Random random = new Random();

    lote = "lote1";
    producto = "producto 1";
    fecha = DateTime.Now.ToString("ddMMyyyy hhmmssf");

    builder = new StringBuilder();
    builder.Append(lote);
    builder.Append(producto);
    //builder.Append(fecha);
    builder.Append(random.Next(50).ToString());

    Debug.WriteLine(builder.ToString());
    Debug.WriteLine(Zipper.Zip(builder.ToString()));

    var plainTextBytes = System.Text.Encoding.UTF8.GetBytes(builder.ToString());
    Debug.WriteLine(System.Convert.ToBase64String(plainTextBytes));
}

public static string Zip(string str)
{
    var bytes = Encoding.UTF8.GetBytes(str);

    using (var msi = new MemoryStream(bytes))
    using (var mso = new MemoryStream())
    {
        using (var gs = new GZipStream(mso, CompressionMode.Compress))
        {
            msi.CopyTo(gs);
        }

        return Encoding.UTF8.GetString(mso.ToArray());
    }
}

lote1producto 123
���/I5,(�O)M.�W042��kg
bG90ZTFwcm9kdWN0byAxMjM=

bG90 ZTFw cm9k dWN0