Raster vs Vector: Definition, Resolution, File Formats, and Uses

Raster images are pixel-based graphics used for photographs and continuous-tone artwork, where image quality depends on resolution, bit depth, color space, and compression. Higher pixel dimensions and bit depth improve tonal range, while improper scaling or heavy compression reduces sharpness and print fidelity. Common raster formats for print and packaging include TIFF and PSD, typically supplied in CMYK at final size to maintain color accuracy. Vector images, by contrast, use mathematical paths that scale without loss, making them essential for logos, text, dielines, and spot-color plates in packaging. Vector quality is resolution-independent until rasterized for output, and formats such as AI, EPS, and PDF/X dominate print workflows. Effective packaging design combines vectors for structure and precision with rasters for photographic detail, using controlled raster-to-vector or vector-to-raster conversion based on artwork purpose and output requirements.

What is a Raster Image?

A raster image, also referred to as raster or raster graphic, is a pixel-based bitmap in which each pixel stores color data and, in some cases, alpha data, so the image depends on a fixed resolution. Raster images record continuous‑tone subjects such as photographs, scans, and painted textures, for example, product photos or scanned artwork. Key traits include pixel dimensions in width and height, bit depth per channel, such as 8‑bit or 16‑bit, and a defined color space, such as sRGB, Adobe RGB, or CMYK. Enlarging a raster beyond its native pixel count reduces sharpness and adds interpolation artifacts. File size increases as pixel count and bit depth increase, which follows the relation bytes = width × height × channels × (bits per channel ÷ 8). Lossless compression keeps pixel values, and lossy compression reduces data at the cost of visible artifacts.

How Does Raster Resolution Determine Image Quality?

Raster image quality depends on pixel dimensions, bit depth, and raster‑to‑print settings such as PPI, DPI, and halftone LPI. Print size follows print inches = pixel dimension ÷ PPI, so a 3000 × 2000 px file at 300 ppi yields a 10.0 × 6.67 inch print. Bit depth shapes tonal steps: 8‑bit per channel creates 256 steps per channel, and 16‑bit creates 65,536 steps, which supports broader correction. DPI describes printer dot density and differs from PPI. Halftone reproduction uses LPI, and the PPI ≈ LPI × 1.5–2 rule sets workable source resolution. Resampling modifies sharpness: nearest neighbor keeps block edges, bilinear softens, bicubic sharpens reductions, and Lanczos preserves edges with fewer artifacts. Compression losses from JPEG, for example, blocking or chroma subsampling, reduce edge precision and complicate plate output.

Which Raster File Formats are Used for Print and Packaging?

TIFF and PSD remain the preferred raster containers for print, and JPEG works for proofs and web, while PNG stays limited to screen use. TIFF supports uncompressed or ZIP compression and handles 8-bit or 16-bit channels with alpha data. PSD stores layered editing data, including masks and adjustments. JPEG applies lossy compression and suits proofs or photographic previews. PNG uses lossless compression and suits web assets with transparency. HEIF and HEIC appear in newer devices, yet printers rarely accept them. Packaging work relies on TIFF or embedded raster inside PDF X with an ICC profile, and supplying images as TIFF at final size in CMYK, such as Coated FOGRA39 or US Web Coated SWOP, keeps color separations stable and prevents unwanted raster conversions.

What is a Vector Image?

A vector image encodes artwork as mathematical primitives made of points, straight lines, and curved segments, so edges and shapes keep their clarity at any size. The file stores geometry as anchor positions, directional controls, stroke widths, and rules that define how filled regions interact. Logos, icons, type elements, and dielines used in packaging rely on this structure because printers read these shapes as precise paths. Vector files record color as process CMYK or as named spot inks, such as Pantone references. They also support non-destructive steps that include clipping paths, compound shapes, and gradient meshes. File weight depends on the number of geometric elements and the complexity of each path. Heavy meshes or embedded raster textures raise processing demands and, in some workflows, trigger rasterization during export.

How Does Vector Output Quality Relate to Resolution?

Vector artwork stays resolution independent, and the final output quality depends on the rasterization settings and the behavior of the target device. Curves keep their edge accuracy at any scale because the system stores them as mathematical instructions, and the visible sharpness only changes when the artwork converts into pixels for a print device or a digital export. That conversion happens during export to TIFF, during RIP processing, or during direct digital printing, and the outcome relies on target PPI, the selected anti-aliasing method, and the color conversion path. Vector text and strokes enter the same pixel grid as photographic elements once rasterized, so the chosen PPI must match the expected plate or print resolution to reduce edge softness or banding. Packaging workflows also depend on precise vector paths for tasks such as die cutting and engraving because these paths carry machine coordinates, and the lines stay functional only when kept as true vector geometry with single-pixel or hairline strokes defined as a non-printing spot color.

Which Vector File Formats are Used For Packaging and Print Production?

AI, EPS, and PDF, especially PDF/X variants, are the standard vector formats for packaging; SVG and CAD formats support specific tasks. AI keeps editable layers. EPS carries older PostScript data. PDF/X‑1a locks CMYK and spot plates. PDF/X‑4 keeps live transparency. SVG handles web icons. DXF and DWG carry die‑line coordinates. Print shops request a PDF/X file with embedded or outlined fonts, named spot colors such as Pantone 186 C, and a separate non‑printing spot‑color layer for dielines.

What are the Technical Differences Between Raster and Vector?

The technical differences between raster and vector images are detailed below:

Scalability

Scalability defines how raster and vector data hold detail at different sizes. Raster images use fixed pixel grids, so enlargement pushes those pixels across a larger area and softens edges. Vector graphics use coordinates and curves, so scaling preserves contour accuracy for logos, dielines, and type.

File size

File size reflects how raster and vector structures store visual data. Raster files expand as pixel count and channel depth increase, so large photographs or 16‑bit artwork create heavy TIFF (Tagged Image File Format) or PSD (Photoshop Document) files. Vector files grow as primitive counts increase, for example, complex meshes or multiple compound paths.

Editability

Editability depends on how each format represents visual elements. Raster editing targets pixels with tools that retouch, mask, or composite photographic data. Vector editing targets nodes, strokes, and filled shapes, which supports clean adjustments to logos, dielines, and type layers.

Color handling

Color handling differs because raster and vector systems encode color in separate ways. Raster artwork stores continuous‑tone color channels suited for photographic images, for example, sRGB or CMYK scans. Vector artwork assigns color values to shapes, including defined spot inks for packaging plate work.

Print reproduction

Print reproduction behavior depends on how each format interacts with halftones and device rendering. Raster artwork converts into halftone cells based on LPI, which affects tonal smoothness in photographs. Vector artwork supplies sharp edges and exact tool paths for foil, cutlines, or emboss plates.

Photorealism

Photorealism capability varies because each format represents texture differently. Raster images carry natural gradients and fine tonal shifts from product photos or scans. Vector graphics lack photographic grain unless a designer embeds rasters or constructs intensive meshes that increase node density.

When Should Raster and Vector Graphics be Used?

Use cases for raster and vector graphics are divided into six functional categories that are detailed below:

Vector artwork for dielines and structural paths

Vector artwork defines dielines, crease paths, and cut paths because those elements depend on coordinate‑based geometry that keeps accuracy at any scale. Vector layers carry non‑printing spot colors such as “DIELINE,” so production teams read them as mechanical guides, and the lines stay aligned with CNC tables or steel‑rule tooling.

Vector graphics for logos, typography, and plate definitions

Vector graphics keep logos, letterforms, and spot‑ink plate definitions sharp because the system stores strokes and filled regions as paths. Vector type avoids stair‑stepped edges when artwork enters a RIP, and spot‑ink values remain linked to named plates such as Pantone‑based reds, blues, or metallic inks.

Raster images for photographs and tonal artwork

Raster images record photographs, gradient‑heavy textures, and complex tonal regions because pixel grids track color variation with precision. TIFF files supply product photos at full resolution, and the pixel data supports consistent color corrections across retail cartons, pouches, or folding boxes.

Raster resolution for close‑view and distance‑view packaging

Raster resolution sets the final print clarity for packaging panels because pixel density restricts scaling. Close‑view panels use 300 ppi to preserve detail in small text or product images, and large corrugated panels use 150–200 ppi because viewing distance reduces visible pixel structure.

Vector plates for path‑based effects and raster plates for tonal effects

Vector plates define foil, varnish, and emboss paths because finishing units interpret each path as a tool boundary. Raster plates define tonal varnishes, textured coatings, or soft‑mask gradients because pixel patterns control density shifts across the surface.

Bleed and safe‑margin setup for print accuracy

Bleed and safe‑margin setup prevent trim errors from cutting key content because print sheets shift by small mechanical tolerances. Bleeds extend artwork 3–5 mm beyond the trim, and safe margins hold text 3–5 mm inside the trim to keep information intact.

How to Convert Raster Artwork to Vector and Vector Artwork to Raster?

Here is how to convert raster artwork to vector and vector artwork to raster:

Raster-to-Vector Conversion

Raster-to-vector conversion traces pixel regions into node-based paths that preserve edge geometry for print and packaging workflows. The process starts with a clean raster source. High-contrast edges, reduced noise, and simplified color regions increase path accuracy. Tracing engines such as Illustrator Image Trace, Potrace, and Vector Magic convert pixel clusters into fills and strokes. Path precision, corner threshold, and noise suppression control node counts. Higher precision increases nodes and raises file weight. Color‑mode tracing breaks artwork into multiple fill objects. Manual tracing with pen tools produces cleaner topology for brand marks, dielines, and barcodes, if the artwork contains hard edges.

Vector-to-Raster Conversion

Vector-to-raster conversion turns curve-based shapes into pixel data at a set PPI, color mode, and compression level for press-ready output. Vector artwork converts during export or RIP processing. Designers pick rasterization PPI by viewing distance: 300 ppi for close-view cartons and 150–200 ppi for corrugated substrates. Live transparency flattens if a RIP cannot process blend modes or soft masks. Exports embed ICC profiles such as Coated FOGRA39 to keep color intent fixed. Compression affects visible artifacts: TIFF ZIP keeps channel integrity, and JPEG adds quantization blocks. Exported PPI stays aligned with halftone LPI, so dot gain compensation and tonal transitions match press behavior.

Can a Low-resolution Raster be Converted to a Vector Logo Suitable for Print? 

Conversion works when the raster file contains clear, high‑contrast boundaries, for example, a scanned one‑color logo, because tracing engines map those pixel blocks into vector paths, and manual redraw corrects warped segments, if the source contains stair‑stepped edges; vector tracing never restores the continuous‑tone detail lost in a low‑resolution photograph.