Lineweight vs ctb

[rmk]

if in the ctb a pen color (red) is assigned a certain size (i.e. .10 mm) and a layer is assigned this color, what affect does changing the layer lineweight from default to a larger size (i.e. .35).

i guess i'm asking which takes control.

[rmk]

So, i've done a little research and it seems if you're using a ctb file the lineweight for a certain color is what controls the width.
if you use a stb file you have more options.

[Tom Beauford]

The out of the box ctb files only have "Use object lineweight" assigned to colors so you should be able to assign lineweights by layer or by object.

Of course stb files are simpler and give you more options. Most of what I do with FDOT.stb (from Florida Dept of Transportation) simply cannot be done with a ctb and it only needs 6 Plot Styles instead of 256 required for a ctb.

[MMccall]

Yeah, a CTB with defined lineweights for color will override layer, and even object, lineweight settings. (note: a polyline with a 'width' can override a ctb)

I use the OOTB monochrome.ctb with lineweight set by the layer. Black to shades of grey are set by layer with the Translucency setting. If I want something in color, I use a color from the color books or a true color. it gives me a lot of flexibility as it can over ride a layer setting at many levels. (override an xref layer, override per viewport) In rare cases I can even force a plotted color or translucency to the object.

[dgorsman]

So, i've done a little research and it seems if you're using a ctb file the lineweight for a certain color is what controls the width.
if you use a stb file you have more options.

I've used the various settings to "play some games". We have a full-size CTB provided by the client which reads lineweights by object, and objects are lineweight BYLAYER, with the layer having the lineweight from the dropdown list; there is also a dictated association of color and lineweight. However, that doesn't work well for 11x17 prints. Yes we could use the "Scale lineweights" option however that leaves precious little difference between thick and thin lines. So for reduced size prints I have another CTB with line weight by color, and line weights set a little heavier at the thick end. We get the best of both worlds.

You don't *have* to set up all colors in the CTB file. It's not uncommon for those who only do schematics or simple 2D plans to use the named colors (1 - 7) and ignore the rest, same as using a select set of named plot styles. Granted, it's advantageous to call a plot style "Text" rather than know it's supposed to be color 3. But you also have to have an STB with all the plot styles with matching names. That can get annoying when a third-party vendor drawing comes in with non-specific names like "Style_1" or "Bill" hard-assigned to objects rather than BYLAYER.

[Tom Beauford]

With the Autodesk-MONO.stb that comes installed with AutoCAD Normal plots in Color, Solid plots black, and there are 9 different grayscales. No need to ever send anyone a CTB or STB as it's installed already. For Civil work here in Florida we rely on Florida DOT standards and specifications so using their FDOT.stb made sense for us. All our templates layers are set up with colors, lineweights, linetypes, and plot styles.

[brian.nixon]

We have a very similar problem that the original post addressed. They tell us to use A/E/C Layer Standards from the Army that have RGB color values and they tell us to use the .CTB pen table from the Naval Facilities Engineering Command. The two don't work together at all and you will get ugly lineweights and wrong color plotting. The best solution is to ignore the RGB color values from the Layer Standards and pick the best color that you can that will plot in the correct color and correct lineweight when plotting with the .CTB file. We are trying to get the DoD criteria changed so we can officially ignore the RGB color values in the A/E/C Layer Standards.

Brian

[Tom Beauford]

We have a very similar problem that the original post addressed. They tell us to use A/E/C Layer Standards from the Army that have RGB color values and they tell us to use the .CTB pen table from the Naval Facilities Engineering Command. The two don't work together at all and you will get ugly lineweights and wrong color plotting. The best solution is to ignore the RGB color values from the Layer Standards and pick the best color that you can that will plot in the correct color and correct lineweight when plotting with the .CTB file. We are trying to get the DoD criteria changed so we can officially ignore the RGB color values in the A/E/C Layer Standards.

Brian

Wow! They gave you a CTB which can't support true colors at all and expect you to use true colors with it?

[brian.nixon]

The CTB they gave us is impractical because most of the colors either: (1) plot in color instead of black, or (2) plot screened 10% or 20% or 30% or 40% or 50% instead of black, or (3) plot in lineweights that are undesireable for our purposes, such as 2.00 mm, 1.40 mm, 1.00 mm, and 0.10 mm. The A/E/C layer standards use quite a few of these colors but at the same time require desirable lineweights such as 0.18 mm, 0.25 mm, 0.35 mm, and also a few 0.50 mm or 0.70 mm. Furthermore, we almost always plot in monochrome. I think of all of the colors designated for use in the A/E/C layer standards, there might be one or two at the most that plot in black and at the A/E/C required lineweight when using the required CTB, since the CTB gets the final say in the matter.

Brian

[tedg]

if in the ctb a pen color (red) is assigned a certain size (i.e. .10 mm) and a layer is assigned this color, what affect does changing the layer lineweight from default to a larger size (i.e. .35).

i guess i'm asking which takes control.

To answer your question.. in the case you describe, the color takes precedence.
If the CTB file you're using is assigning a lineweight to color red, that's what will plot.
I think if a polyline has a width assigned, I think that overrides it.

But, as Tom mentioned, CTB files also have the option to use "object lineweight" (which means lineweight assigned to the object, or it's layer, in that order).
In this case, in my opinion, it's best to keep the object's lineweights to ByLayer (vs. assigning lineweights to objects).

For example: I believe the NCS 4.0 ctb file uses "object lineweights" and all colors are assigned as black except the grayscales 250-255.
So color doesn't matter in this case, (except the gray scales mentioned) layers have your desired lineweights built in.
NCS 3.1 and below, had colors with lineweights you would normally se