The hatch command in AutoCAD fills materials and sections, and its alias is H. But most people searching for it are not stuck on calling the command — they are stuck because the fill comes out wrong, or they are hunting for new patterns without knowing how many the installation already carries.
The number worth knowing first: the acadiso.pat file in the 2027 release defines 83 patterns, one solid fill and 82 line patterns. A great many people go looking for a library before exhausting what is already installed. To learn modelling and documentation end to end, see the AutoCAD for construction course.
Where to start the hatch command
Four ways in, read straight out of the 2027 configuration files.
| Route | Detail |
|---|---|
| Full command | HATCH |
| Alias | H, and also BH |
| Ribbon | Home → Draw → Hatch drop-down → Hatch |
| Classic menu | Draw → Hatch |
| Toolbar | Draw → Hatch |
| Command line version | -HATCH, asks everything at the prompt |
Two aliases point at this one command. The ordinary form opens a contextual ribbon tab rather than a dialog, which is friendlier to look at but harder to put in a script.
The prompts, step by step
The -HATCH form shows everything the command can do. Before asking, the program prints Current hatch pattern: ANSI31, the pattern in force.
| Step | What the program asks | What you do |
|---|---|---|
| 1 | Specify internal point or [Properties/Select objects/draW boundary/remove Boundaries/Advanced/DRaw order/Origin/ANnotative/hatch COlor/LAyer/Transparency]: | Type P to set pattern and scale first |
| 2 | it asks for the pattern name, then scale, then angle | Enter the three values in turn |
| 3 | back to the step 1 prompt | Click a point inside the area to fill |
| 4 | the same prompt again | Click the next area, or Enter to finish |
Two things follow.
Step 3 needs only a point inside, and the program traces the boundary around it. That boundary has to be closed, which is the number one reason the command reports a failure.
Pattern and scale are remembered, so filling a run of areas in one material is just step 3 over and over.
Six material symbols already installed
Construction drawings use hatching to tell materials apart. There is no single mandatory symbol table, but there is a set of conventions most Vietnamese offices follow, and every symbol in it already has a pattern.
| Material | Built-in pattern | Notes |
|---|---|---|
| Cut brickwork | ANSI31 | Lines at 45 degrees. The most familiar symbol on Vietnamese drawings |
| Reinforced concrete | AR-CONC | Dots and aggregate. Overlay ANSI31 on the same region for reinforced concrete |
| Blinding concrete | SACNCR | Or AR-SAND for a sand bed |
| Natural ground | EARTH | For the soil below a foundation |
| Sand | AR-SAND | A random dot pattern |
| Gravel | GRAVEL | |
| Timber | GOST_WOOD or JIS_WOOD | The two differ in grain density |
| Insulation | INSUL | |
| Floor tiling | NET square · AR-PARQ1 parquet · AR-HBONE herringbone | |
| Solid fill | SOLID | Concrete columns at small scale, once the hatch lines crowd together |
Three groups can be ignored for building work: names beginning ACAD_ISO follow the ISO standard, JIS the Japanese standard, GOST the Russian one.
One requirement many drawing sets forget: a hatch symbol needs a legend beside the title block. A builder cannot tell brick from concrete by the hatching alone.
Calling the command: four options, two interfaces
The Hatch button sits on the Draw panel of the Home tab. Type HATCH, or H, or BH. The 2027 prompt carries four options.
Pick internal point or [Select objects/Draw/Undo/seTtings]:
| Option | What it does |
|---|---|
| Pick internal point | The default. Click inside a region and the program traces the boundary |
| Select objects | Pick the boundary objects directly. Use it when the boundary is already a closed polyline |
| Draw | Draw a new boundary and fill it in one go. A newer option, handy when no boundary exists |
| seTtings | Opens the Hatch and Gradient dialog, the older interface |
The 2027 release has two interfaces, chosen by HPDLGMODE. It defaults to 2, a contextual ribbon tab. Set it to 1 and the old dialog returns, which gathers every field in one place and is easier to take in at a glance. See the HPDLGMODE (System Variable) page.
Hatch scale: the cause of both a black blob and an empty region
This is where most fills go wrong, and it produces two opposite symptoms that people mistake for two separate faults.
The same ANSI31 pattern on three identical squares, differing only in scale:
| Scale | Line spacing | Result |
|---|---|---|
1 | 3.175 units | Solid black — the lines overlap each other |
40 | 127 units | Readable; this is a usable value |
400 | 1270 units | Almost empty — one line of the pattern is longer than the region |
The rule: a black blob means the scale is too small; an empty fill means the scale is too large. Both are fixed with the Scale field, not by changing pattern.
Angle is the second field. Note that the angle you enter is added to the pattern's own angle: ANSI31 already runs at 45 degrees, so entering 45 makes 90 and the lines stand vertical.
Hatch origin: the fourth field nobody notices
The three fields above decide how the pattern looks. The fourth decides where it starts, and it only shows its hand when you fill floor tiling or brickwork.
A hatch pattern is not glued to the region it fills. It is an infinite grid spread across the whole drawing, and the command simply clips the part of that grid falling inside the region. The anchor of that grid is the hatch origin, set to 0,0 in a new drawing and readable through HPORIGIN.
The consequence: fill a 600 by 600 tile pattern anywhere and the first tile is almost certain to be cut short, because the edge of the region does not land on a grid node.
The Origin option offers three routes:
| Route | What it does |
|---|---|
| Use current origin | Keeps the existing origin. The default |
| Set new origin | Pick a point as the new origin. The command then asks Store as default origin? |
| Default to boundary extents | Uses a corner or the centre of the region's bounding box. Handy for rectangles |
Answer No to Store as default origin. Yes changes the origin for the whole drawing, so later fills elsewhere come out misaligned. The origin belongs to one hatch, not to the drawing.
For floor tiling, set the origin at a corner of the room and check where the cut tile falls. A builder needs to know which edge the tiling starts from. This is where a hatch stops being decoration and becomes construction information.
Island modes and boundary gaps
An island is a closed shape inside the filled region — a column in a room, a stair void in a slab. The program handles islands three ways.
A fresh 2027 install uses Outer, and for building work that is the right mode: fill a slab and columns and stair voids are left clear.
Gaps are the second issue. Draw a region from four lines with one falling a few units short and clicking inside returns:
Valid hatch boundary not found.
The Gap tolerance field, the HPGAPTOL variable, lets the program overlook gaps smaller than the value you set. It defaults to 0, forgiving nothing. Set 10, run the command again, and the fill appears as though the shape were closed. See the HPGAPTOL (System Variable) page.
One more trap on a real plan: the column grid runs along the centre of the wall, so the wall is split in two by the grid line. Click exactly on the grid and the program refuses with Point is directly on an object. The tidiest answer is to switch off the grid layer before filling, so the full wall thickness becomes one region.
Associative: the fill follows its boundary
Associative is on by default, HPASSOC equals 1, and it should stay that way. The fill then tracks its boundary: edit the boundary and the fill follows.
It can be measured: stretch the right-hand wall out by 600 and the fill extends, with the Area field in Properties moving from 2,240,000 to 2,480,000 — exactly the extra wall length.
To edit an existing fill, type HATCHEDIT, alias HE, or simply double-click it. The Properties palette, opened with Ctrl and 1, edits every value without calling a command and reads out the area as well. Editing options, associative hatches and splitting a shared hatch are covered in editing hatches in AutoCAD.
Inherit Properties is the biggest time-saver in the dialog: click it, then click an existing fill, and you take its pattern, scale and angle wholesale.
When the 83 supplied patterns are not enough
Before downloading anything, type -HATCH, then P, then a question mark and Enter: the program lists every pattern currently available with its description. Often the one you want is already there.
Where that list falls short, the next step is to add hatch pattern definitions of your own from a downloaded .pat file. This is where most people get stuck, because every custom pattern has to sit in its own file named after the pattern. The Institute's set of 12 material patterns, packaged that way, together with the measurement showing why a combined file fails, is in our article on an AutoCAD hatch pattern library.
Reading area from a filled region
A hatch is not only for looking at. Select one, open the Properties palette, and the Area field reads out a figure that already excludes the islands inside — more accurate than measuring by hand.
There are three ways to read area: the Properties palette for a single region, the LIST command which prints area, perimeter and vertex coordinates, and the AREA command which adds and subtracts regions through its Add area and Subtract area options.
One source of error that keeps appearing in schedules: area is reported in square drawing units. On a drawing in millimetres one square metre is one million units, so divide by a million to reach square metres.
A workable routine for a house drawing set:
- Build a boundary for each room with
BOUNDARY, clicking once inside. Put those boundaries on their own layer and switch it off when plotting. - Select each boundary and read the Area field.
- Divide by a million for square metres.
- Write the figure into the schedule.
- Cross-check: the rooms plus the walls must equal the gross area. More than a few percent out means a room has been missed or two boundaries overlap.
Frequently asked questions
What is the alias for the hatch command in AutoCAD?
Type H and press Enter. The command-line form is -HATCH, which asks for pattern, scale and angle in turn before the pick point.
Why does my fill come out solid black?
The scale is too small, so the pattern lines overlap. Raise the Scale value rather than changing pattern.
Why does nothing appear after hatching?
The opposite: the scale is too large, and one line of the pattern is longer than the region. Lower the Scale value.
Why does the program say it cannot find a boundary?
The boundary is open. Set HPGAPTOL to 10 and try again, or rebuild the boundary with BOUNDARY.
I downloaded a hatch library and it does not work. Why?
Check the four conditions: pattern name under 31 characters, a blank line at the end of the file, the file inside the Support File Search Path, and the file name matching the pattern name. The tidiest fix is to paste the pattern into acadiso.pat.
Related articles
- What is AutoCAD — a handbook for people working in construction
- Object snap in AutoCAD — why snapping ignores hatches by default
- The ZOOM command in AutoCAD — zooming, and three jobs confused with it
- Construction drawing symbols — the conventions used across a drawing set