The TileWidth property returns or specifies the horizontal size of a pattern tile, measured in document units.
Examples:
The following VBA example applies a two-color bitmap pattern to a tile that is 3" wide × 1" high.
Sub Test()
Dim s As Shape
Dim pf As PatternFill
Set s = ActiveLayer.CreateRectangle(0, 0, 4, 4)
Set pf = s.Fill.ApplyPatternFill(cdrTwoColorPattern, , 8)
pf.TileWidth = 3
pf.TileHeight = 1
End Sub