Illustrator: Scale all strokes in a document without touching object and pattern size?

Question

I have an illustrator file (actually it's a map) which has lines, polygons and some patterns. I would like to scale the stroke width of all lines (also lines inside patterns) by 80% without altering the patterns or the size of the objects.

When using the Scale tool I must chose one of "transform objects" and "transform patterns" but I don't want to scale any of those, only Strokes.

I could first scale everything by 80%. Then I could scale it by 133.333333% and leave out "strokes & effects". The problem is that lines in patterns stay the same.

When I toggle "transform patterns" the size of the patterns changes including the stroke widths, but I only want the stroke widths to be altered.

So does anyone know how to solve this?

I do not want to have to select individual objects since there are thousands of them.

Answer 1

You can try this: Open your text editor (the best is ExtendScript Toolkit, installed with Illustrator by default), then past in new document the text below.

//here you can change the stroke percentual
var myA = prompt("Choose your %","80","Change width stroke");
var myPercentile = myA/100;

if(myA!=null){

    // choose all page elements
    for (var i=0;i<app.activeDocument.pageItems.length;i++){
        var myLayer = app.activeDocument.pageItems[i];

        //if element is compound make a new loop for pathItems
        if(myLayer.typename=="CompoundPathItem"){
            for(var u=0;u<myLayer.pathItems.length;u++){

                //take actual stroke size
                var myPath = myLayer.pathItems[u];
                var myMeasure = myPath.strokeWidth;

                //transform the stroke width into % choose at start
                myPath.strokeWidth = myMeasure*myPercentile;
                }

            }

        if(myLayer.typename=="PathItem"){
                var myMeasure = myLayer.strokeWidth;
                myLayer.strokeWidth = myMeasure*myPercentile;
            }
        }
    }

Save the doc wherever you want with .jsx extension. Back in Illustrator and open the file to change, in File menu, choose Script > another script... and choose the file .jsx

Hope it works for you

Answer 2

• Select one object with a stroke.

• Choose Select > Same > Stroke Weight

• Enter the value for the stroke you want.

• Choose Object > Hide

• Repeat until all objects are hidden.

• Choose Object > Show All

There is no built in way to independently scale strokes of different weights which I'm aware of.