12 replies to this topic

[Justin]

I am using Illustrator CS3, and I have MAPublisher and ArcGIS as well. I need some tips on suppressing linework. This may be super easy but I can't figure it out!

I have a very busy map that needs to be cleaned up a bit. I have a background layer, roads, and type for city names. I'd like to break the road layer as it nears the city name type and have it start up again on the other side, maybe a buffer of 4 or 5 pixels.

I can do this manually. I can also turn the road stroke into a polygon and use the Illustrator pathfinder to knock it out from an invisible buffer around the outlined type, but that only will work one time per road line. My goal would be to have a single road line broken at 40 or 50 points along its path (the roads are not important to the map). This would also be something I'd like to learn to break a coastline at coastal city names or icons.

I know how to make a halo, but i'd prefer that the shaded relief show through all the way to the type.

I'd like to do this on the roads and type layers only, leaving the shaded relief and other layers untouched.

Little help? Tips?





*I always get into trouble for posting things that are already being talked about in another thread, but I'll have everyone know I looked and looked and didnt see this one.

[Matthew Hampton]

It sounds like a Feature Outline Mask in ArcGIS is what you are looking for. I think you'll need an Info license.

[David Medeiros]

I have never actually done it, but I think there is a way to use clipping masks to block the linework in one layer against another while letting all other layers show through. You might be able to create the masks using the type by copying all the type to background, incresing the stroke to create the appropriate sized knock-out, creating outlines of the type and using the newly creted type polygons as a clipping mask.

[sitesatlas]

I have never actually done it, but I think there is a way to use clipping masks to block the linework in one layer against another while letting all other layers show through. You might be able to create the masks using the type by copying all the type to background, incresing the stroke to create the appropriate sized knock-out, creating outlines of the type and using the newly creted type polygons as a clipping mask.

David is onto one possible solution. Clipping masks block out everything in a layer that falls outside the masked object, which is the opposite of what you want. What you need here is a big clipping mask with holes around the text, so that the lines you want knocked out are inside the holes. You'll need to copy that mask on to all the layers you want to knock out.

First, copy your text and change it to paths. Then, offset the paths the way you want the knock-out effect to look. The original text outlines will still be there, so select those and the new, offset paths and use the Pathfinder unite command to fuse overlaps together. Draw a rectangle the size of your document and select both it and the text shapes you just fused (make sure the rectangle is above the text shapes) and do a Pathfinder exclude operation to create the holes. Copy this new shape to the top of all the layers you want to knock out, then create clipping masks with it.

This is kind of clunky. The biggest drawback is that if you ever edit your text, you have to redo the whole process. Let's hope someone has an easier and more efficient method...

[Justin]

I have never actually done it, but I think there is a way to use clipping masks to block the linework in one layer against another while letting all other layers show through. You might be able to create the masks using the type by copying all the type to background, incresing the stroke to create the appropriate sized knock-out, creating outlines of the type and using the newly creted type polygons as a clipping mask.

That sounds like an excellent solution, i'm going to try it.

What prompted this was a book called "Introduction to Cartography" I bought at the ESRI UC last week. There was a note about suppressing linework and I thought "oh, thats what it's called"... i'll post a reply when I try these methods.

[David Medeiros]

I have never actually done it, but I think there is a way to use clipping masks to block the linework in one layer against another while letting all other layers show through. You might be able to create the masks using the type by copying all the type to background, incresing the stroke to create the appropriate sized knock-out, creating outlines of the type and using the newly creted type polygons as a clipping mask.

That sounds like an excellent solution, i'm going to try it.

What prompted this was a book called "Introduction to Cartography" I bought at the ESRI UC last week. There was a note about suppressing linework and I thought "oh, thats what it's called"... i'll post a reply when I try these methods.

I've always know it as a "knock out" or k/o. I use a simpler version under any type that crosses a line by either clipping the line and deleting the inner portion or adding a line behind the type set to the background color. I believe it is a term from the print world where layers on a press plate will either overprint or knock out the ink from plates beneath it.

[Hans van der Maarel]

Martin wrote a great set of instructions for overprinting in Illustrator a few years ago. Maybe that's the trick?

[sitesatlas]

Martin wrote a great set of instructions for overprinting in Illustrator a few years ago. Maybe that's the trick?

That technique looks great! It's quick and easy, and if you don't have to change text to outlines, then you can still edit your labels without messing everything up. So the complex clipping mask technique I described would only be necessary if you have to knock out two or more layers.

[Justin]

Well, thanks to you guys I figured it out - and it's a lot easier than I thought!

Here is a quick step by step, along with before and after photos ...

1. I finished all the type on my map. In this example, i'm using a highway map of New York State. The city name type was on the same layer as the city 'dots', so I just left them together for my experiment. Next time I will keep city name type on its own layer. I suppose this would work with multiple type layers, but I just used the cities for now.

2. I created an box around the extent of the map on its own layer on top of all other layers, the box had no stroke and no fill. I named this layer "mask".

3. I copied the city name layer (and the dots...) and used 'paste in front' to place it on the mask layer with the invisible box.

4. I outlined all of the type.

5. I used path -> offset to offset everything by .1 inch. I then set the fill and stroke to everything on the layer to blank.

6. I created a compound path with everything on the mask layer (the offset type, city dots, and the box around the map)

7. I locked all of the layers except the state highways and the mask layer, and then made a clipping mask.

Voilà! Suppressed linework. In the future when I have more time I guess this would work with any linework that would need to be cut out from type and other elements. This was just a simple experiment, but it worked very well.

I have uploaded before and after images to this reply.


* I searched for 'knock-out' and such, too... but I worked in the printed/commercial map industry for many years and whenever we used the term knockout it was purely for preprint or print separation setups. If you search for knockout relating to Illustrator, thats all you will get, unfortunately. I figured 'suppressed cartographic linework' would be a more industry-specific term.

Attached Files

•  before.gif   102.15K   39 downloads
•  after.gif   70.1K   47 downloads

[David Medeiros]

As far as I understand it Knockout (or Knock-out) is the term used to describe what you are looking for, the ability to block art work in particular areas beneath other artwork without breaking or deleting any line work. I did a 10 year stint at AAA of Northern CA on printed maps and thats were I learned the term and technique, but you're right it may not be industry specific. Nothing wrong with your wording, I was just trying to give you another term for it.

If you do a search in the Illustrator help forum for knockout you'll get quite a few entries with various work flows. Some of them may be appropriate to this thread, I haven't really gone over them in detail.

http://community.ado...m...n_US&area=0

dave

[Charles Syrett]

Looks like a useful technique, but I have to say I don't understand why you felt it was needed on this map. To me, the first sample looks just fine as it is. It makes no sense to me to knock out grey lines under black text.

About the terminology: "knockout" was the expression cartographers used for this, years before Illustrator was a twinkle in Adobe's eye. We would overexpose a contact positive from the type in the darkroom, and then use that as a mask ("knockout") when exposing the scribecoats of whatever linework needed it. Funny how some effects became simpler with computers, and others became more complex.

Charles Syrett
Map Graphics
http://www.mapgraphics.com

[Justin]

Looks like a useful technique, but I have to say I don't understand why you felt it was needed on this map. To me, the first sample looks just fine as it is. It makes no sense to me to knock out grey lines under black text.

Ahhh, well, it was not needed on this map. I just picked an AI file at random to experiment on. I'm working on another map that has a really crazy background (it's a school project of wind speeds in Texas) - and I put roads on it to analyze the distance wind turbine farms are being built from major highways, and I wanted to knock the roads out from around the wind farm icons. I just had a New York map I had made laying around and used it to test.

At Thomas Guides / Rand McNally, the term 'knockout' was used when we wanted to knock out everything behind something, and thats fine, but I wanted to knock out the roads with a buffer, leaving certain layers untouched. I can take everything out -like a "clip"- but I couldnt figure out how to preserve certain layers or create that buffer (until now!). We'd use that for print separations and setup, before we switched to a digital print vendor. I was probably just not searching for the correct terminology when attempting to learn how to do it.

We should make a glossary.

[David Medeiros]

At Thomas Guides / Rand McNally, the term 'knockout' was used when we wanted to knock out everything behind something, and thats fine, but I wanted to knock out the roads with a buffer, leaving certain layers untouched. I can take everything out -like a "clip"- but I couldnt figure out how to preserve certain layers or create that buffer (until now!). We'd use that for print separations and setup, before we switched to a digital print vendor. I was probably just not searching for the correct terminology when attempting to learn how to do it.

We should make a glossary.

I'd still consider that a knockout, just one that knocks out a slected set of artowrk instead of all underlying artwork. Your experince at Rand is probaby the same as mine at CSAA in that they never did anythting this compicated.

And YES, we should make a glossary! When I left CSAA (more accurately, when they dumped our department) I took a book called the Glossary of Geosciences (I think). Large and very arcane but interesting. It would be greast to have a similar work focused more specifically on Cartography and GIS mapping.