Printing with TextOut API not working

Hi,

I making a ticketing program that prints tickets with different 'watermark label' in certain conditions.
I used Printer Object in printing the data because I used continuous tractor feed (DOT Matrix EPSON L300+ II)
To Print watermark since its impossible with just using Printer.Print method, I used the TextOut API with some modifications
to make it Tilt to a specified degree. (I got the codes from MSDN). To solve the transparency problem I used a lighter color
that is gray. When I tried the code, the watermark doesn't show. So, I thought I have done it wrong. But I double checked
everything and there seemed to be nothing wrong in my code. So I tested it with different printers. It worked with printers
and even saving the print jobs to file (OneNote and MS XPS Document Writer) it works. Except on my dot matrix printer.

Can anyone help me with my problem?

And by the way, I also tried to find out if the DOT Matrix Printers (Impact Printers) support the TextOut API.
But I found nothing even something that has any relation to my problem.

Please. Please. Youre help is pretty much appreciated. :(
Thanks in advance.