Combining Objects into Blocks - AutoCAD 2011 and AutoCAD LT 2011: No Experience Required - page 309

color and linetype of the layer that is current when the block is inserted or the layer
to which you move the block. Objects on other layers retain the properties of their
original layers, regardless of which color or linetype has been assigned to the current
layer. This is one characteristic that distinguishes layer 0 from all other layers.
TIP the objects that compose blocks can reside on more than one layer.
While it's technically possible to create blocks on any layer of your choice, the
generally accepted best practice is to always define blocks that are to be used as
symbols in a drawing on layer 0. It is also recommended that the color, linetype,
and lineweight each be set to ByLayer or ByBlock. Drawing your blocks with
these properties in mind does a number of things.
First and foremost, it helps ensure that when you insert a block on a given
layer, the block functions as if it were drawn on that layer. By using the ByLayer
or ByBlock settings, you help avoid the confusion often experienced with colors
and linetypes in blocks. In the coming exercises, I'll show you how to follow these
best practices while converting some of the objects already in your drawing into
blocks and creating some new blocks of your own. To get started, you'll see how
to create blocks from objects already in your drawing. You'll create a block for the
exterior swing door first, using the back door, and call it A-DOOR-36IN to match
the NCS naming convention used throughout this topic. For the insertion point,
you need to assign a point on or near the door that will facilitate its placement as
a block in your drawing. The hinge point makes the best insertion point.
For this chapter, the Endpoint osnap should be running most of the time, and
Polar Tracking should be off. Follow these steps to set up your drawing:
1. Continue using the 06A-FPLAY9.dwg drawing you created in the last
chapter. If you're starting a new session, you can download this file
from the topics website at www.sybex.com/go/autocad2011ner , or
www.autocadner.com .
2. Click the Layer drop-down list, and click the sun icon for the
A-WALL-HEAD layer to freeze it. Then click the A-DOOR layer to
close the list.
The A-DOOR layer is now current, and the sun next to the A-WALL-
HEAD layer turns into a snowflake. In addition to the A-WALL-HEAD
layer, the A-FLOR-FIXT and A-ROOF layers should still be frozen from
the previous chapter (see Figure 7.2).