how can I speed up a specific macro?

[cjcass]

Hi,
I have the code below which works fine but am looking to see if anyone knows of a way to speed it up - it currently takes around 12 secs to run.
You will notice that the ranges all have the same row numbers.
Many thanks.

Application.ScreenUpdating = False
For Each c In Range("K23:K56,AC23:AC56,AU23:AU56,BM23:BM56,CE23:CE56,CW23:CW56,EG23:EG56,EY23:EY56,FQ23:FQ56,GI23:GI56,HA23:HA56,HS23:HS56,IK23:IK56,JC23:JC56,JV23:JV56,KM23:KM56,LE23:LE56,LW23:LW56,MO23:MO56")
    Select Case Len(c)
        Case 80 To 130
            c.Font.Size = 10
        Case 131 To 150
            c.Font.Size = 9
        Case Is > 150
            c.Font.Size = 8
        Case Else
            c.Font.Size = 11
    End Select
Next
Application.ScreenUpdating = True

 

[cjcass]

Ok, seemed to have found the issue but can't understand why it created a problem...
Completely independent from the sheet I'm working in with this macro (Sheet18) and the wksheet that Sheet18's formulas are reading from, there was a picture in another wksheet that was linked to a group of cells in yet another wksheet. I've just been systematically removing elements of wksheets (tables/pics/code etc.) to see if I could identify the problem and it was a linked picture - when I deleted the picture this the code above runs in a flash - but weirdly it's not connected in any way??
The downside is that I would like to keep the picture I have deleted and it's link to the cells in another wksheet - is there maybe some code I can use that only updates the picture when I want (so it's not 'live').
Any thoughts or ideas much appreciated.

 

[cjcass]

ok, sussed it.
I have isolated the linked picture via named ranges.
Thanks again for all your help