Printing Only Rows With Non-blank Cells

I am trying to print only the non-empty rows in my sheet ("1"), so I am checking every row from row 1 to row 500 to determine if that row is empty, in that case it will be hidden temporarily, then I will PrintPreview only non hidden rows. Finally, I will unhide all rows.

The problem is that although the following code works, it takes forever to run due to large number of rows. Based on sheet design, once the first empty row is discovered, all the following rows beneath it are all blank by default, so all I really need to do is automatically hide all the rows following the first discovered blank one without checking them, then proceed with PrintPreview as above. Sometimes my 3rd row is blank, so I could save a lot of time by automatically hiding rows 3 to 500 without checking them.

code below:

Sub Hide_Print_Unhide()
Dim rw As Long
Application. ScreenUpdating = False

With Sheets("1")
For rw = 1 To 500
If Application.WorksheetFunction. CountA( _
. Cells(rw, 1).Range("A1:C1")) = 0 Then _
.Rows(rw).Hidden = True
Next rw
.PrintPreview ' for testing use .PrintPreview
.Range("A1:A500").EntireRow.Hidden = False
End With

Application.ScreenUpdating = True
End Sub