Paper (Layout Tab)This is Paper Space — your sheet of paper at 1:1. Everything here is measured in inches or mm. Title block, border, and notes live here.
Viewport (MVIEW)A window into Model Space. The scale you set here controls how much of the model is visible. Lock it after setting scale.
Title Block AreaDrawn at paper size in Paper Space. Never scale this — it should always be full size.
Model Space vs Paper Space — The Core Concept
Think of it like this: Model Space is the real world — you draw everything at 1:1 true size. A 30-foot wall is 30 feet long in model space. Paper Space is the print sheet — a D-size sheet is exactly 34"×22" in paper space. The viewport is a camera lens: it zooms in on model space and projects it onto the paper at your chosen scale. You only set the scale once, in the viewport. Everything else — linetype scales, annotation heights — adapts automatically when set up correctly.
Model Space Rules
Draw everything at true real-world size. A building column at 18" is 18 inches. A utility pole at 40 feet is 40 feet. Never scale your geometry.
What
In Model Space
Geometry
Full real-world size (1:1)
Text height
Plotted height × Scale Factor
Dimension scale
DIMSCALE = Scale Factor (or Annotative)
Hatch scale
Pattern scale × Scale Factor
Linetype scale
LTSCALE = Scale Factor
Paper Space Rules
Paper Space is always 1:1 to the print sheet. A 34" wide D-size border is drawn 34 inches wide here. Text in Paper Space is placed at the actual plotted height — no scaling needed.
What
In Paper Space
Border / title block
Actual paper dimensions (1:1)
Notes on sheet
Actual plotted height (e.g. 0.125")
Viewport border
Drawn in paper space, any size
Scale label
Text like "Scale: 1/4" = 1'-0""
PSLTSCALE
Set to 1 so linetypes scale to paper
Step-by-Step: Setting Up a Viewport
1
Open a Layout tab
Right-click a Layout tab → Page Setup → set your plotter and paper size. This defines the sheet boundary in Paper Space. Delete the default viewport AutoCAD creates (it's usually the wrong size).
2
Create a viewport with MVIEW
Type MV (MVIEW alias) → pick two corners to define the viewport rectangle on your sheet. Or use VPORTS for preset configurations.
3
Activate the viewport (double-click inside)
Double-clicking inside enters Model Space through the viewport. The viewport border thickens. Now you're looking at your model through the lens.
4
Set the viewport scale with Zoom XP
Type Z → then enter the XP factor shown in the result band above (e.g. 1/48xp for 1/4"=1'-0"). This is the most reliable method — it sets the zoom so 1 paper unit = the correct model units.
5
Pan to position your drawing
While still inside the viewport, use Pan (P) to center your drawing in the viewport. Do NOT zoom — that will change your scale.
6
Lock the viewport scale
Double-click OUTSIDE the viewport to return to Paper Space. Select the viewport border → Properties panel → set Display Locked = Yes. This prevents accidental zoom changes. Alternatively, right-click the viewport border → Display Locked → Yes.
7
Set PSLTSCALE = 1 and CANNOSCALE
In Paper Space, type PSLTSCALE → set to 1. This makes linetypes display correctly in the viewport. Then set CANNOSCALE to match your viewport scale so annotative objects display at the right size.
Viewport Scale — Two Methods Compared
Zoom XP Method
Recommended
Type Z → enter 1/SFxp (e.g. 1/48xp)
Direct, precise, no dialog
Works in all AutoCAD versions
XP = times Paper space — 1/48 of model = 1 paper unit
Easiest to verify: zoom 1/48xp exactly sets 1/4"=1'-0"
Custom Scale List / VPSCALE
Also valid
Select viewport → Properties → Standard Scale dropdown
Or VPSCALE command in some versions
Easier for non-technical users
Scale must exist in the scale list (SCALELISTEDIT)
Can add custom scales via SCALELISTEDIT
Never zoom with the scroll wheel while inside a locked viewport. Double-click outside first to exit the viewport, then scroll. Zooming inside a locked viewport will break your scale and you'll have to reset it.
Zoom XP Quick Reference Table
Scale
Scale Factor
Zoom XP Command
CANNOSCALE
Discipline
Layer Freeze per Viewport
One of paper space's most powerful features: you can freeze different layers in different viewports. A site plan viewport can show grading layers while a detail viewport hides them — same model, different layer states per view.
1
Activate the viewport (double-click inside it)
2
Open the Layer Manager (LA). You'll see a new column: VP Freeze (the snowflake icon in the current VP column).
3
Click the VP Freeze icon for any layer you want hidden in this viewport only. It freezes in this viewport but stays visible in all others.
4
Return to Paper Space (double-click outside). The frozen layers are invisible in that viewport, visible in others.
Defpoints layer tip: Objects on the Defpoints layer never plot, making it useful for viewport borders, construction lines, and reference geometry you want visible on screen but not on the print.
System Variables Reference
Multiple Viewports — Layout Strategy
Viewport Type
Typical Scale
Purpose
Notes
Overall / Key Plan
Smaller (1/8", 1:100)
Show full extent of project
Often in corner of sheet
Main Plan
Standard (1/4", 1:50)
Primary working view
Largest viewport, centered
Detail
Larger (1"=1', 1:5)
Zoomed-in critical areas
Multiple per sheet common
Elevation / Section
Same as main or different
Vertical views
Match scale to plan when possible
3D / Isometric
N/A or 1:1
Visual reference only
Lock and annotate in paper space
Common Mistakes & Fixes
Problem
Cause
Fix
Linetypes look solid in viewport
PSLTSCALE = 0, or LTSCALE wrong
Set PSLTSCALE = 1, LTSCALE = 1, then REGEN
Scale changed after panning
Scrolled while inside viewport
Re-enter viewport, ZOOM 1/SFxp, re-pan, re-lock
Annotative text not showing
CANNOSCALE doesn't match viewport scale
Set CANNOSCALE to match viewport scale in Annotation Scale dropdown
Viewport border plots
Viewport border layer is plottable
Put viewport borders on a non-plotting layer (e.g., VPORTS or Defpoints)
Questions & Tips
Share a viewport workflow tip or ask a question — shown after review.