Bonjour DJFA,
Si j'ai bien compris ta demande, voici une proposition :
Sub MEF()
Dim i As Integer
With Selection
i = 1
Do Until i >= .Rows.Count
.Offset(i, 0).Resize(2, .Columns.Count).Borders(xlInsideHorizontal).LineStyle = xlContinuous
.Offset(i, 0).Resize(2, .Columns.Count).Borders(xlInsideHorizontal).Weight = xlThin
.Offset(i, 0).Resize(2, .Columns.Count).Borders(xlInsideHorizontal).ColorIndex = xlAutomatic
i = i + 4
Loop
End With
End Sub
A+