Only if you want to show the same element at different scales with different pen thicknesses.
For example we place a perimeter around our buildings which we use in plan at 1:100 and also on the site plan at 1:200.
On plan I want thin lines because there I see all the walls anyway.
On the site plan I need a thicker line because there are no walls showing and I want to highlight the perimeter line to make it stand out.
So the choice I have is to use a particular pen number for that perimeter line and make sure that I have 2 pen sets - one where the pen is thin and the other where the pen is thick.
Easy enough but I have to remember to use that particular pen for the perimeters and make sure I don't use it for anything else if I don't want the thickness to change at different scales (asuming the element shaows at both scales).
Another option is to have just the one pen set and magic wand a thicker line around the perineter that only shows up in the site plan layers.
Very easy to do but the downside here is you now have 2 perimeters to adjust if you need to change your building plan.
You will always know if you have to adjust the second thicker line as it won't match the original perimeter and if you make sure both these lines show on your site plan you should spot the problem straight away and it is very easy to adjust (espescially if they are different colours).
There is probably no perfect solution.
It is all about what suits you best.
One thing I do like to set up an extra pen set for is printing.
I have a printing pen set where I change the colours to black or grey and I can also leave some coloured if I want to.
Of course white pens remain white so they don't print.
Then I use this for the drawings in my layouts and I can still print in colour but get black/grey prints with a splash of colour if I need it.
The black/grey pen set(s) are a duplicate of the plan pen set(s) - same pen thicknesses just different colours.
Barry.
One of the forum moderators.
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