调用代码：

//不同的打印机需要不同的参数，这个参数应该可以在打印机的编程文档中找到
string str = ((char)29).ToString() + ((char)86).ToString() + ((char)0).ToString();
byte[] p_Byte = System.Text.Encoding.Default.GetBytes(str);

string p_PrintName = "打印机名称";
WinApiPrintByte(p_PrintName, p_Byte);

方法：

/// <summary>
/// 发送数据到打印机
/// </summary>
/// <param name="p_PrintName">打印机名称</param>
/// <param name="p_Byte">切纸数据</param>
public static void WinApiPrintByte(string p_PrintName, byte[] p_Byte)
{
    if (p_PrintName != null && p_PrintName.Length > 0)
    {
        IntPtr _PrintHandle;
        IntPtr _JobHandle = Marshal.AllocHGlobal(100);
        if (OpenPrinter(p_PrintName, out _PrintHandle, IntPtr.Zero))
        {
            ADDJOB_INFO_1 _JobInfo = new ADDJOB_INFO_1();
            int _Size;
            AddJob(_PrintHandle, 1, _JobHandle, 100, out _Size);
            _JobInfo = (ADDJOB_INFO_1)Marshal.PtrToStructure(_JobHandle, typeof(ADDJOB_INFO_1));
            //System.IO.File.WriteAllBytes(p_PrintName, p_Byte);
            System.IO.File.WriteAllBytes(_JobInfo.lpPath, p_Byte);

            ScheduleJob(_PrintHandle, _JobInfo.JobID);
            ClosePrinter(_PrintHandle);
            Marshal.FreeHGlobal(_JobHandle);
        }
    }
}

[DllImport("winspool.drv", CharSet = CharSet.Auto)]
public static extern bool OpenPrinter([MarshalAs(UnmanagedType.LPTStr)]string strPrinterName, out IntPtr ptrPrinter, IntPtr ptrDefalut);

[DllImport("winspool.drv", CharSet = CharSet.Auto)]
public static extern bool ClosePrinter(IntPtr ptrPrinter);

[DllImport("winspool.drv", CharSet = CharSet.Auto)]
public static extern bool AddJob(IntPtr ptrPrinter, Int32 iLevel, IntPtr ptrJob, Int32 iSize, out Int32 iCpSize);

[DllImport("winspool.drv", CharSet = CharSet.Auto)]
public static extern bool ScheduleJob(IntPtr ptrPrinter, Int32 JobID);

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
public struct ADDJOB_INFO_1
{
    [MarshalAs(UnmanagedType.LPTStr)]
    public string lpPath;
    public Int32 JobID;
}

说明：本段代码来源于网络。

        在热敏小票打印机打印机上测试可用

        看原文介绍，应该也可用于其他带有切纸刀的打印机