AutoCAD wasn’t quite the first mechanical drawing program to separate drawings into layers, but it was one of the early adopters of this practice. Layers (and layering) are an incredibly powerful tool in AutoCAD (and in several other applications, like Photoshop and Illustrator).

Today, I am going to show you how to use layers to make your AutoCAD work flow easier to manage, easier to organize and more enjoyable!

First of all, the basic concept of layers is really simple. When you drag windows over each other in, well, Windows, you’re putting some windows “on top of” other windows. The same thing applies with AutoCAD, except that you have a lot more control over the layers, can make some of them transparent, and can move drawing elements from one layer to another.

One way to think of layers is as “a clear plastic sheet”. You can lift certain layers to view only other layers and specific materials. To manage layers we use the Layer Properties Manager button, which looks like a little icon of three sheets of paper stacked one atop the other.

Each layer has a color associated with it – this is the color the line segments will show when that object is selecte. You can also vary the line type, line weight and also lock, unlock or hide layers so that they’re out of the way. You can define if a layer is to be printed (you can make layers display that don’t print, or ones that print that don’t display.)

By default, AutoCAD puts your drawing elements on a layer called “0″, and sets this as the current layer (you can use the Layers palette to change which layer is “current”). You should immediately make a new layer, and assign it a name. When you’re doing a complex drawing, like say a set of building plans to build a boat, label each section and put them into separate layers. This allows you to turn layers on or off (make them visible or invisible) or even shuffle them, to see how things overlap or interact. This is an incredibly powerful tool…but it’s only as powerful as you make it.

Another trick you can do to make your layering experience more useful is that AutoCAD allows you to group layers together and make “sublayers”. If you’re doing drawings that have line segments and fills, consider putting the line segments on one layer and the fills on another. This allows you to select a sublayer, hit Ctrl A (select all) and change colors of the fills at once. Do this for all commonly grouped elements, and you’ll be able to adjust nearly anything in a blink of an eye. (Nothing in AutoCAD is as tedious as hand selecting a bunch of objects, tweaking them, finding you’ve missed one, and having to do it over, and over and over again.)

The third trick that layers let you do is to move objects between layers. This alone is a life saver. If you forget to assign something to a layer or choose the wrong layer it is a big help to be able to just move it to the desired layer.

Ok, that is the rundown on layers. I will be doing a video up on layers very soon so if there was anything you didn’t understand that should sort it out. Try searching for the video in the search bar.

What is the Polyline Command?

Very few people remember what it was like to do mechanical drafting before AutoCAD hit the market. When I talked to a colleague a few days ago it was amazing how much things had changed since the manual days. I took a mech drafting class or two in college, but, honestly, if you handed me a T square and a French curve, I’d probably wonder where the mouse buttons are.

One of the things that really brought home the difference between mechanical drafting the old way and AutoCAD is line segments and polylines. The Polyline tool is up on the Drawing toolstrip, next to the Draw tool., and looks sort of like a fish hook with dots along its length.

What does the Polyline Command do?

What polylines do is create line segments that have some level of automation and object awareness in them. You use the Polyline tool to draw shapes – each time you “complete” a shape, or part of a shape (and deselect it) it automatically groups all the segments into one item that can be clicked on, resized and dragged around. You can identify objects made by polylines by the blue “handles” or “grips” on the corners in the drawing area.

However, there’s more to polylines than grips and handles – remember the reminiscing about mechanical drafting? Well, one of the things that eats time for draftsmen doing it the old fashioned way is erasing and adjusting line segments, and getting those changes propagated across an entire drawing.

With polylines, that becomes much simpler – albeit a bit counter-intuitive. Because AutoCAD gives you the ability to enter coordinates to start polylines with, you can specify arcs, tangential segments, and stroke widths. Sometimes, this is much more efficient than drawing with the mouse – sometimes, you need to do some trial and error to make it work.

When you specify the start point, you’re given a choice for the next point on the line – an Arc/Halfwidth/Length/Undo/Width choice. You’ll be selecting the first letter of the word, in Upper Case text. To draw a blob (like a lake), enter A for Arc. The line segment immediately turns into an arc. You can select a bunch of other segments until it’s close to the shape you want; to close off the polyline object, enter CL to close the segments (note that this is a two letter command, and is case sensitive!)

Note also that when the Arc command is selected, you get a choice of options that pops up. You can play with the Radius, miter limits and a number of other options. The best way to find out what to do is to just play with the tools for a bit. It’s the equivalent of being a kid with magic markers all over again. Don’t worry about getting something productive out of it – learn where everything is and see what everything does for now.

Moving past Arcs, there are other traits that polylines have. One of the more useful ones is Width. After selecting the polylines command again, draw an object with a polyline, and hit W. You have the option to select the width of the polyline numerically. This is comparable to the stroke of the line with a pen nib (something else I’d forgotten about mechanical drafting!), and allows you to get almost calligraphic with your line weights. One of the neat things is that AutoCAD will ask you for the width of the start of the line, and then ask for the width of the end of the line – you don’t have to use the same width. This is a great way to get a lot of flexibility in drawing your line segments with this program, and the more you use it, the more uses you’ll see for it.

So what are you waiting for?

Start using the polyline command in your drawings today and stop wasting your precious time drawing things manually that don’t need to be.

Now, if you liked this tutorial check out the categories to the right for more or sign-up for my free 5-day AutoCAD Course.