Viewing Distance, DPI & Print Quality for Signage

Why DPI Works Differently for Signage

In traditional printing (business cards, magazines, packaging), DPI is everything. Small prints are viewed up close, so every detail matters.

Signage is different.

• Most signs are viewed from 1 metre to over 20 metres away

• Your eye cannot resolve fine detail past a certain distance

• Large-format printers layer colour differently from photo printers

• Material texture and finish affect perceived sharpness

• Higher DPI is not always necessary — or even visible

This is why a billboard printed at 15 DPI still looks sharp from the road.

More technical preparation details are discussed in our Artwork & File Preparation guide.

Understanding DPI in Large Format Printing

What DPI Actually Means

DPI stands for “dots per inch” — the number of ink droplets placed within a one-inch space.

Large-format printers use:

• bigger nozzles

• variable droplet sizes

• overlapping colour passes

• controlled dithering patterns

This allows them to create smooth gradients and clean lines at much lower DPI than small printers.

Typical Large-Format DPI Ranges

Here’s what most signage printers use:

• 150–300 DPI — Posters, interior signage, reception acrylics

• 100–150 DPI — Shopfronts, wall graphics, window graphics

• 45–100 DPI — Large ACM panels, building signs

• 10–30 DPI — Billboards, high-elevation signage

Anything beyond what the viewing distance requires is usually invisible.

Viewing Distance: The Most Important Factor

The further away you stand, the less detail you can see — this is how human vision works. That means DPI should scale with distance.

Close-Range Signs (Viewed 0.5–2 metres)

Examples:

• reception signage

• office acrylic panels

• indoor branding

• small interior prints

Recommended: 150–300 DPI

These installations are viewed closely, so finer detail matters.

Mid-Range Signs (Viewed 2–7 metres)

Examples:

• shopfront windows

• wall graphics

• interior panels

• window decals

Recommended: 100–150 DPI

Full photo crispness is unnecessary at this range.

See more under Window Graphics.

Long-Range Signs (Viewed 7–20+ metres)

Examples:

• large ACM fascia

• external shop signs

• building signage

• high-mounted outdoor panels

Recommended: 45–100 DPI

Your eye simply cannot see the difference beyond this point.

See practical examples in ACM Panel Signs.

Vector vs Raster: Why It Matters for Print Quality

Vector Artwork

Vector files use anchor points and paths, meaning they can scale infinitely without losing quality.

Ideal for:

• logos

• text

• simple illustrations

• geometric shapes

• branding elements

Vectors always print crisp, regardless of size.

Raster Artwork

Raster files (JPEG, PNG, TIFF) are pixel-based.

Good for:

• photos

• textures

• gradients

• backgrounds

Raster requires the correct resolution at the final output size.

Common Issues Caused by Low Resolution

Pixelation

Blocky edges from insufficient DPI.

Soft or Blurry Edges

Usually from enlarging a small raster file.

Jagged Text

Occurs when text is rasterised instead of vector.

Compression Artefacts

Often seen in over-compressed JPEGs.

Patchy Gradients

Occurs at low DPI or when artwork uses banding.

These issues are usually fixable by supplying vector artwork or high-quality raster files.

How Much Resolution Do You Actually Need?

A simple and reliable reference:

• A4 flyer: 300 DPI

• Interior acrylic panel: 200–300 DPI

• Wall graphic: 120 DPI

• Shopfront window: 100–150 DPI

• Ute/van signage: 100–150 DPI

  See examples under Vehicle Graphics.

• Large ACM exterior sign: 75–100 DPI

• Building banner: 30–60 DPI

• Billboard: 10–30 DPI

• 
  

Anything higher than required for the distance provides zero visual benefit — and only increases file size.

How Material Type Affects Perceived Sharpness

Not all materials display detail the same way.

Matte Vinyl

Softens edges and reduces contrast.

Gloss Vinyl

Appears sharper due to reflectivity.

Textured Surfaces

Concrete, textured walls, and uneven substrates reduce visibility of fine detail.

ACM + Laminate

Provides the crispest finish due to smooth, flat, rigid surface.

One-Way Vision Film

Images appear softer because of the perforated holes; best suited for bold graphics.

See more in One Way Vision Graphics.

Frosted Vinyl

Always diffuses detail due to surface texture.

Material choice should match the type of artwork and expected viewing distance.

Scaling Artwork: Avoiding Quality Loss

Large-format graphics often require scaling. Here’s how to do it correctly:

• Always design at the final aspect ratio

• Avoid stretching artwork horizontally or vertically

• Do not upscale raster images beyond 150–200%

• Use TIFF or high-quality JPEG for photos

• Keep text vectorised wherever possible

• Avoid repeatedly exporting files through different software (quality degrades each time)

• Supply artwork at print scale or with a clear scale ratio (e.g., 1:10)

Proper scaling ensures crisp final output even at large sizes.

When High DPI Does Matter

Some signage needs sharper detail because of close viewing or optical effects.

High DPI recommended for:

• reception acrylic panels

• detailed artwork

• illuminated signs (LEDs enhance detail)

• high-end interior graphics

• small text viewed up close

When High DPI Does NOT Matter

High DPI adds no visible improvement for:

• shopfront signs viewed from the street

• building signage

• ACM fascia panels

• vehicle graphics viewed in motion

• wall wraps viewed from across a room

For these, mid or low DPI is completely acceptable.

Summary: Choose DPI Based on Distance, Not Perfection

Large-format printing works differently from small-scale printing. DPI should always be determined by:

• viewing distance

• artwork type (vector vs raster)

• substrate texture

• lighting conditions

• sign purpose

By choosing the right resolution for the right distance, you get sharp, professional results without unnecessary file sizes or production delays.

See more guides in the resource hub