Layer Names and Line Defaults

Organizing and simplifying layers in CAD. May 19, 2004

Question
How do you approach layer naming?

I've been looking at national CAD standards, but it seems too cumbersome for what we need. I'll spell out my layer names and conventions in another post.

I used to use a default linetype of .007, and .004 for dimensions. I've since switched to .007 for fine, .010 (default) thin, .014 medium, .020 wide, and .050 for borders.

Forum Responses
(CAD Forum)
From contributor R:
I set up the layer standard for the company I work for and basically used the NCS as an example, then simplified it and adjusted it to our needs. I tried to group our layers together in relation to what was on them. (Granted I do not work for a woodworking shop or for an architect, so this might not work in your case. I work for a civil engineer, land surveying company.) So I group all of the paving, grading, utility, storm drain, and existing features topo layers together by using prefixes such as PA for paving, GR for grading and so forth, similar to what the NCS does. I would try to use this system regardless of discipline. Once you get used to it, it works great! And as far as cumbersome, I would rather see a layer name that explains what is on that layer than see 4-8 letters that don't mean anything to me.



From the original questioner:
Thanks for your response.

I think in the cabinetmaking industry, simplicity is probably best. I wouldn't be surprised if there are guys out there with only 3-4 layers. I set up our layering system, and here it is, as I promised:

0


A_bWDWK
A_CASE
A_cTXT_
A_cTXT-FS
A_DIM
A_DIM-FS
A_DRS-DRW
A_HATCH
A_HIDDEN
A_NOTES
A_SYMB
A_WALL
A_zAPPL
A_zELECT
A_zFIXT
A_zHDWR
A_zNPLT
A_zTBLOCK
Defpoints

I start everything with an A- that way I can immediately identify any stray layers if they wander in from a cut and paste, or a block. I use small case sub-letters for arranging them into most used layers at the front. The naming conventions I took from national CAD standards when it was available.

I like the way you resolved your situation with the prefixes. Looks to be a great idea. What do you use for lineweights in your industry? What is your default line weight?



From contributor S:
Sorry, but I disagree with you. I think any discipline is going to want as many layers as possible, much like contributor R has suggested. Our base template for woodworking starts with over 90 layers. Our full architectural template begins with over 300. This may sound daunting, but it really isn't. Layer naming standards makes is pretty easy. Layer management is the key to detailed and clear drawings and being able to handle many layers.

A big help to layer names is an add-on application that expands the layer drop down. Go to www.cadwerx.net and look up FixCombos. DocBar is good also.



From contributor A:
I like the minimalist theory. We use only 10 predefined layers (including 0, defpoints, and a separate viewports layer) and occasionally will add a couple more if the situation requests it. Contributor S, I do respect you (many fine posts), but I gotta say - 300 layers sounds a tad much. Just a tad. I'll not throw out the idea, though, and will check out cadwerx.

We just use a primary layer, a secondary layer (lighter) and dimensions (two like the original questioner, one for all dimstyles and one for full scale dimensions), a hidden layer, a text layer, and a few others. All layers have a specific distinguishable color. Makes it easy to know what layer stuff is on just by looking at it.

I am personally over the top about not accumulating unwanted blocks, layers, and the like cluttering up a drawing.



From contributor S:
Contributor A, thanks for the support. It doesn't really matter much if you have 3 or 300 layers. It's how you structure them and use them. If your layer names are standardized, you can do some pretty cool and quick drawing changes. For instance: say you name all of your layers for walls *_WALL_*****. (ex: A_WALL_EXIST and S_WALL_SHEAR. A_ is for architectural and S is for structural, similar to national CAD standards. And the prefixes will group the layers in the list.). You can then build a toolbar button to lock WALL layers. This is good for stretching objects that lie within walls, but does not include walls; and also allows you to not accidentally stretch wall elements. This list of benefits is endless. We have buttons for all sorts of filtering like this. You can quickly organize drawings and views, especially if you use the Express Tools Layer Manager. In other words, you can turn off an entire group ("S") with one click, or even all WALLS within all groups, if you want to.

One important aspect of this concept is what some gurus call "stacked drawing". This is where you draw stuff on top of stuff, on top of stuff, and so on. (Since you have seen some of my previous posts, you probably know what I am talking about). Being able to draw this way (efficiently) is fantastically accurate, and very real world, and what separates CAD from just electronic drafting. But, you have to have layer management. Once you have set that up, it's all rewards.

The example above is for architectural, but just as easily adapted for casework.

The reason templates are initially setup with so many layers is so that staff does less thinking about adding layers and layer naming.



From contributor A:
Contributor S, I have been talking with our guys for quite a while about changing the way we structure our layer standards. Maybe now is the time. "It's how you structure them and use them." Yes, I couldn't agree with you more. You guys have really perked my interest in taking our standards up a notch.

I can really see the advantage of stacked drawing, but will have to work out how we will best use it. It'll be tough to give up layers having a specific, distinguishable color, but I can see how layer filtering might make that irrelevant.

Thanks for the original post. Definitely a productivity boosting topic. I like your layer naming strategy and may combine both your ideas.

Oh, ya know why I limit to ten layers? Cause the 11th makes a scroll bar in the drop down window. I know, I know, it's really anal. I checked out cadwerx. Cool looking stuff - thanks for the tip.



From contributor S:
CadWerx FixCombos takes care of that nasty layer drop down. It increases the height to the bottom of the graphics screen and widens it a bunch. You can have long layer names that really mean something.

As for the colors, it takes some thinking and testing. Use a white background, if you don't already. That gives you more contrast. Use the same color for same types of layers; like text layers are maybe always blue and wall layers are always 32. Play around with colors and layers until you get the right blends with contrast in the grouping of layers that are viewed together most of the time. It can be done, just takes a little trial and error. Then make a template, and a CAD standard that no one messes with the colors.

As you've guessed, I think layer setup, standards, and management are the core to good CAD work. Layering is all too often underrated.

Stack drawing also has its opponents, although I am a firm believer. Maybe we can get more feedback on that.

Here's another interesting observation: By far the most comments on this site are AutoCAD related. People have obviously chosen CAD to do their work, and are not choosing software packages (CabnetWare, etc.). Or, they have gone MicroVellum or use multiple software in their operations, like Acad for drawing and Pattern Systems for cutlisting, etc.



From contributor R:
As far as line weights, we have several. I think it is the old way of doing things, but they are associated with our colors in a .ctb file. We use everything from a .015 to .05 and if we need anything thicker than that, we use polylines with width. This has been up for discussion quite a bit here lately due to the new color capabilities that A2K4 has, but I'm not real interested in changing things and having to train 50 users that now lineweights are associated with layers instead of colors. While I can see the benefits, folks here don't exactly embrace change.

As far as our layers and the simplicity of them, they are as simple as they can be with the size projects that we do and we still will have upwards of 300 layers in a project base. However, for the woodworking jobs that I draw up, I can get away with many fewer layers. The rule that I live by on layers is make it simple for stupid people. I want anyone who is not familiar with our system to be able to come in and pick up this system and embrace it in a short period of time. As far as the number of layers, that is determined by how many things you want to be able to isolate. Regardless of the application, I hate to try to isolate something and have a bunch of clutter still remaining in the drawing that I don't need.



From contributor I:
When I work in 3d in Autocad, I use more layers than in 2d. I use names like rib, skin, stretcher, and so on. To keep layers unique, I use a prefix. This is nice when doing a set-up drawing. In paper space, I freeze layers in view ports only, and then show unassembled views by using viewports. With dashed lines and arrows I’ll show a set-up. I don’t follow a layering standard but I try to keep it simple.