Transparent text with canvas

Hello I’m using xojo on windows and am trying to create a transparent text with a class of type canvas. I created 2 picture: one designed with the red text and the other the same text in black.

Image 1

Dim tmp As New Picture(Width,Height,32) tmp.Graphics.ForeColor=&cFF0000 tmp.Graphics.DrawString "Hello",8,10

Image 2

Dim tmp1 As New Picture(Width,Height,32) tmp1.Graphics.ForeColor=&c000000 tmp1.Graphics.DrawString "Hello",8,10

I then assigned to the picture as a mask the second image and the transparency works correctly.

tmp.Mask=tmp1 g.DrawPicture(tmp,0,0,Width,Height)

The problem is that the text you see grainy, how do I fix?