Ok, took a little while to figure it all out, but the following placed in the Paint event will give you 45 degree diagonals both ways that fill the defined area:

```
Var spacing, ax1, ay1, ax2, ay2, x1, x2, y1, y2 As Integer
spacing = 10
//define area to draw, starting at ax1,ay1 (upper left) to ax2,ay2 (lower right)
ax1 = 25
ay1 = 25
ax2 = ax1 + 87 //area is 87 wide
ay2 = ay1 + 45 //area is 45 tall
//draw / lines from x1,y1 (lower-left) to x2,y2 (upper-right), starting from upper-left corner of area
x1 = ax1
y1 = ay1 + spacing
x2 = ax1 + spacing
y2 = ay1
While x1 < ax2 Or y1 < ay2 Or x2 < ax2 Or y2 < ay2
g.DrawLine(Min(x1, ax2), Min(y1, ay2), Min(x2, ax2), Min(y2, ay2))
y1 = y1 + spacing
If y1 > ay2 Then
If x1 = ax1 Then x1 = ax1 + (y1 - ay2) Else x1 = x1 + spacing
End If
x2 = x2 + spacing
If x2 > ax2 Then
If y2 = ay1 Then y2 = ay1 + (x2 - ax2) Else y2 = y2 + spacing
End If
Wend
//draw \ lines from x1,y1 (upper-left) to x2,y2 (lower-right), starting from upper-right corner of area
x1 = ax1 + (((ax2 - ax1) \ spacing) * spacing) //highest multiple of spacing that is within width
y1 = ay1
x2 = x1 + spacing
y2 = ay1 + (x2 - ax2)
While x1 > ax1 Or y1 < ay2 Or x2 > ax1 Or y2 < ay2
g.DrawLine(Max(x1, ax1), Min(y1, ay2), Min(x2, ax2), Min(y2, ay2))
x1 = x1 - spacing
If x1 < ax1 Then y1 = y1 + spacing
y2 = y2 + spacing
If y2 > ay2 Then
If x2 > ax2 Then x2 = ax2 - (y2 - ay2) Else x2 = x2 - spacing
End If
Wend
```

If you want angles other than 45 degrees, it will take some additional calculating and logic.