Topic: Question regarding using CTB vs Lineweights

[StykFacE]

This is a long time question I've had, and I'm sure that I might know the right answer but I would like to get real people feedback on the issue. Question as follows....

I came into my office with certain standards already in use. One of them being that we use a CTB plot style configured by the CAD guy before myself years ago. My ultimate question is, what is the main difference in using a custom CTB plot style vs. giving objects a physical Lineweight in the model? Also, when using a physical Lineweight on an object while using a CTB Plot Style, does one override the other?

Just trying to clarify this longtime question of mine. Thanks 

[jnieman]

A quick test shows that LINEs with a lineweight are overridden by the CTB.

PLINES with a global width, override the CTB, however.

*edit*

to me if you assign individual objects a lineweight, you're wasting time.  That requires far more work that would be avoided by having layer standards and an automated CTB. 

If they set lineweight by layer, and have layer standards... well maybe since it's already set up it'd work just fine, however, I'm not sure as I've never worked in that scenario.  Maybe STB's would be better for them if they like setting lineweights bylayer and ignoring colors.

[New Shooz]

We use CTB's in conjunction with setting color (sp?) and lineweight using Layer Manager.
I am not concerned at all with being restricted to a certain number of colors (sp?), as a normal person's eye will not be able to tell the difference between a true color (sp?) and an AutoCAD color (no more than 256)

[StykFacE]

Okay well let me ask this: Is there any advantage to using one way vs. the other? Is there a good breakdown on using Lineweights vs. CTB files anywhere on the net, or could someone give a good explanation?

[Keith™]

Well, we have had extensive discussions on STB vs. CTB here at theswamp. I still like STB because you can manipulate objects individually. Do a search for "STB CTB" and you will see many.

[jnieman]

I'm fond of CTB because... we're already set up for it

CTB basically works like this:

When plotting, the CTB file is read, and every object is plotted to a lineweight that associates it's color to a thickness in the table.  For 'standards' one would logically set their objects to ByLayer and thus the color would be whatever you set the color to in the layer manager.  This allows you to have color overrides, so that you can change the color of the individual object if you want it to be thicker/thinner than standard for some reason.  These individual color overrides take precedence over the CTB.  This has a drawback though.  If you override a color, and that drawing is xref'd into another drawing, you cannot set that object to shade by turning the xref'd layer to a shaded color... because it no longer cares what the layer color is; it has been overridden.  However, I don't know that STB would solve this...

CTB has a benefit (subjective benefit) of being able to quickly know how something will plot, by seeing what color it is.  STB has the same, if'n you just check what layer it's on, afaik... but I find the color correspondence quite nice.  I'm just comfortable with it.  My brain can quickly see what is on the screen, and come up with how it will plot, without having to plot-preview or check layers or what not.  If all objects are set ByLayer (as they should be, subjectively) then you can also quickly assess if there are objects on the wrong layer.

I do not think that setting each individual object's plot properties (color, thickness) per object would be feasible at all if you use xref's and ever want something to show differently on one sheet, as opposed to another that it is xref'd into... because then you wouldn't be able to control it separately.

After reading many discussions on the site about CTBs, STBs... my conclusion was that they do pretty much the same thing with very little different... and the differences that exist are so minute compared to the overall picture and function that it seems to me that either is equally functional and beneficial... it's just whichever suits your brain, I guess.

[StykFacE]

Thanks jnieman for the description.

I have but one more question now (I know, sorry!!  ).... What good does giving an object in MSPACE/PSPACE a Lineweight, when the CTB/STB file is going to override it anyways? Is it simply just to toggle the Lineweight Display ON/OFF toggle when drawing?

[jnieman]

If using a CTB/STB, you would not ever use the actual lineweight setting.  I don't even have it displayed on my toolbars in fact.

If you wish for an object to be a different lineweight than it's normal state (bylayer) than you would change the color, for an CTB standard or... I'm not sure what to do for STB as I've never worked in an STB environment.  Maybe you can't!  That'd be a plus for some people, I'm sure.

All I tested was a CTB scenario, when I reported the hierarchy or overrides regarding line or pline settings.

The lineweight display ON/OFF toggle only works if your lines are set to a linewidth other than 0.  This does not include any settings that may be passed on via STB/CTB.  STB/CTB are plot styles, and thus only occur during plotting afaik.

The only exception is that sometimes I will use a polyline with it's ACTUAL PHYSICAL width, such as if I have a pipe that is 24" diameter, and I wish to show it 24" diameter, I will give it a global width of 24"... rare case, but I've done it for some things before... actual specific application escapes my memory though, at the moment.  That's not even a case of lineweights or plot styles though, but rather a polyline with a width.

[Bob Garner]

I frequently do design study drawings where I want to have some objects print out in color for identification purposes, but I want the lineweights independant of the color so the correct lineweight is shown regardless of the color.  In this case, I set the lineweights by layer and assign objects to their proper lineweight layer.  An example:  Layer 3 may be a 0.1" lineweight, then Layer 3 is subdivided into Layer 3 Foundation Plan Object Lines, Layer 3 Floor Plan Object Lines, etc.  Layer 2 may be 0.05" lineweight so there would be Layer 2 Foundation Plan Centerlines, and on and on.  The layering identification takes some forethought.  I don't necessarily recommend this for others but it works for my purposes on study drawings.

Bob G.

[StykFacE]

So, the only real reason on having a physical Lineweight attached to an object that will be utilized is when you specify it in the CTB file. But there's no real benefit one way or the other - it's per application under personal preference. So, it goes like this:

CTB = Color Dependent
STB = Layer Dependent
Physical Lineweights = used ONLY if color is specified as ByLayer in the CTB file, if not then it's overridden.

Right? lol 

[Bryco]

I have used lineweights to adjust a hidden line spacing within a block, so there are other reasons.

[mjfarrell]

I have used lineweights to adjust a hidden line spacing within a block, so there are other reasons.

LTSCALE; for hidden line spacing? or line weights?

[sinc]

After reading many discussions on the site about CTBs, STBs... my conclusion was that they do pretty much the same thing with very little different... and the differences that exist are so minute compared to the overall picture and function that it seems to me that either is equally functional and beneficial...

At some point, I should probably try to put together an article on STBs, which illustrates some of the things that STBs can do that CTBs cannot do.  STBs are actually significantly more-powerful and flexible.

There are some quirks and drawbacks to STBs.  We really need the ability to specify a percentage of the object weight in the STB file, and we cannot.  For example, I should be able to create a Plot Style named "half-width", and set it to use "50% of object lineweight", and things like that.  Unfortunately, we can only select "Use object lineweight", which is very limiting.

But even with that limitation, STBs are still significantly more-flexible than CTBs.  I know that after using STBs for a while, I strongly dislike CTB-based drawings, and would never choose to use them again.

[jnieman]

I tried hard at one time, but couldn't find anything to make me think that... and as you can probably tell by my limited post, that I don't know it all about STBs  

I'd be very much interested if you were to write it... but I know how hard it can be to actually make time to do so.

[StykFacE]

At some point, I should probably try to put together an article on STBs, which illustrates some of the things that STBs can do that CTBs cannot do.  STBs are actually significantly more-powerful and flexible.

I would absolutely love this. I want to know if switching to STB plot styles would benefit my company or not. I'm sure there's something like this already out there on the web somewhere, but it's hard to search through the junk to find a good article....  :ugly: