Lines, Layers, Colors

Steve Hunter

Whether you're a new CAD user starting out through the portal of opportunity that IntelliCAD has brought to engineering, or a jaded lifer, still doing time a CAD workstation, CAD Essentials gives you a chance to recap core elements of CAD. 

IntelliCAD, lines, colors, layers, prototype. template, setup, WinLINE, plotting, printing

The last CAD Essentials looked at using Wizards and templates to start new drawings. While it represents additional work, setting up your own drawing templates is ultimately far more productive. This is because well-developed templates contain layer, color and linetype settings that reflect your working practices and save time with every drawing you create.

Now we review the basics of using colors to get you started on the right track. You need to establish a system that works for you but also makes sense to others who may work with your files. The best approach is to start with your preferred color system and build this into a layering convention.

Color — your judgment
In a CAD system, colors are most commonly used to represent line weights. Selecting different colors is just like picking up pens with varying line thickness. We then tie these colors into layers to control the visibility of drawing components.

There are no right and wrong coloring systems — but there are some that have become more prevalent than others. Drafting managed quite well for centuries before CAD came onto the scene. It's hardly surprising then that the most common color system has its roots in a well-established manual drafting system. Many offices have adopted the ISO/DIN line weight color coding system commonly seen in the identification the bands of drafting pens as follows:

• 0.18mm Magenta
• 0.25mm White
• 0.35mm Yellow
• 0.50mm Red/Brown
• 0.70mm Cyan/Blue
• 1.00mm Green

Changes to this system have, in the main, come about as a result of preference for light or dark screen background within CAD. Naturally, yellow doesn't work well on a light background and brown's difficult to see on a dark background.

Tip — Use the OPTIONS or PREFERENCES commands to change the background color

The system above is simple and it works but, with 256 colors to choose from, many companies adopt more complex systems that allocate groups of colors to line weights.

Printing line weights
In order to use pen widths with IntelliCAD 98, you need to install the WinLINE plotter driver — this driver allows you to allocate pen widths to screen colors for standard Windows printers. You'll find this driver on the CD in the directory \IntelliCAD 98\Drivers\Printers, along with some instructions. For a common printer, such as the HP LaserJet 5MP, this adds a new HP-GL/2 printer icon to the printers available within Windows. HP-GL/2 is a printing language developed by Hewlett-Packard that incorporates advanced features such as line weights and filled regions.

To use this printer in IntelliCAD 98, start the PRINT command and enter Print Setup from the Print Settings dialogue box. This displays the Print Setup dialogue box, where you can select the HP-GL/2 printer driver. Selecting the Properties button then allows you to scroll down and change the width and color settings for up to eight pens. At this point you can also nominate whether you will print in color, grayscale or black and white.

Changing the pen settings in the printer setup.

The SETCOLOR command allows you to nominate the current color from a selection of 256 colors. This can be accessed through the Settings toolbar or by entering the SETCOLOR. The COLOR command allows you to enter a color number and displays a prompt menu with the seven basic colors for quick reference. Most commonly, however, we nominate colors for use with layers and leave the current color setting as BYLAYER. This means that the current color is always associated with the current layer.

Setting the current color

Layer Colors
Layer settings are most easily accessed using the IntelliCAD Drawing Explorer. You can enter the drawing explorer with the EXPLORER command, or go directly into layers with EXPLAYERS. Select a layer and then edit its properties using the right mouse click or by selecting  from the Edit  > Properties from the menu. Select a layer color and check again that the current color setting is BYLAYER.

Using layer properties to modify the layer colour

This approach of associating colors with layers provides a flexible system that allows color settings to be changed for different printers or to suit the requirements of different clients.

Now that we understand what colors are about, the next step is to link our preferred colors to a layer structure. Visit again next month when we'll explore layers and tie the two together.

Steve Hunter

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