What are Blocks?
Static Blocks, Dynamic Blocks, Write Block, Redefining Blocks, Exploding Blocks
By definition, a block is a collection of objects (lines, arcs, circles, text etc.) that form a more complex entity that normally represents an object in the real world e.g. a door, a chair, a window, a computer.
You can build up a library of blocks consisting of the parts that you require many times in your workday. These blocks can be stored in a separate folder and even on a network, so that all drafters have access to them. Think of plumbing parts, valves, elbows etc. as well as electrical symbols or furniture.
Blocks can also contain non-graphical information. These are text objects called attributes. For example, you have made blocks of different computers. You can add information to the block such as monitor size, amount of RAM etc. This information stays with the block, but can also be extracted to a database or spreadsheet. This would be useful for things such as a bill of materials. Attributes can also be visible or invisible in your drawing. Another good use of attributes could be a title block.
You can insert blocks into your drawings in several ways including the Insert command, the Tool Palettes and the Design Centre.
Zero Layer has special properties. When creating blocks, if the objects in the block are drawn on Zero Layer, they will assume the properties of the current layer when they are inserted. Example: If you draw the computer below on Zero layer and insert it on the COMPUTERS layer, it will assume the colour, linetype and lineweight of the Computers layer. If you drew and created it on the ‘DOOR’ layer and inserted it in the Computers layer, it would retain the properties of the Door layer. For this reason, blocks are drawn on the Zero layer – you need them to assume the layer’s properties, whether it is in your template, or the client’s.
A line within a block with colour BYLAYER on layer "Linework" gets the colour assigned to layer "Linework".
A line within a block with colour BYBLOCK on layer "Linework" gets the colour assigned to the block.
A line within a block on layer 0 with colour BYLAYER gets the colour of the layer the block is inserted on.