Offset Printing

Offset Printing

Offset Printing

1. What is Offset Printing?

Offset printing is a planographic printing technique where the image is transferred:

Plate  → Blanket→ Paper 

Instead of direct contact between plate and paper, the rubber blanket ensures:

• Higher quality,
• No damage to the plate,
• Accurate registration,
• Ability to print on uneven surfaces.

Offset uses CMYK inks and can include Pantone spot colors.

2. Offset Printing Techniques
3. Sheet-Fed Offset (Tabaka Ofset)

Used for:

• Packaging boxes
• Paper bags
• Brochures
• Magazines
• Cartons (Bristol, Duplex, Folding Boxboard)

Features:

• Prints on sheets (not rolls)
• High color precision
• Can print on thick materials (60–450 gsm)

Advantages:

• Best for packaging
• Perfect registration
• Supports special effects (foil, emboss, spot UV)

1. Web Offset (Rotary Offset / Web Ofset)

Used for:

• Newspapers
• High-volume magazines
• Flyers

Features:

• Prints on continuous paper roll (bobin)
• Extremely fast
• Cheaper per unit for large quantities

1. Offset UV Printing

Used when:

• High-gloss surface is desired
• Fast curing is needed
• Non-absorbent materials (PVC, PET, synthetic paper) must be printed

Benefits:

• Instant drying with UV lamps
• Crisp, sharp details
• Rich, vibrant colors

1. Waterless Offset

Used for:

• Ultra-high detail
• Environmentally friendly production

Uses silicone-coated plates with no water in the printing process.

3. Offset Printing Process Step-by-Step
4. Prepress (Ctp Preparation)

• Graphic design is prepared in CMYK + Pantone
• Trapping, overprint, bleed adjustments
• Color management
• CTP (Computer-to-Plate) plates are imaged

Plate Types:

• Thermal CTP plates (most common)
• UV CTP plates
• Waterless plates

2. Inking & Dampening Systems

A typical sheet-fed offset machine has:

• Ink rollers (ink train)
• Dampening rollers (su haznesi)

Ink and water balance is crucial.

3. Printing Units

Each color (C, M, Y, K, Pantone) has a separate unit.

Flow:

1. Plate cylinder
2. Blanket cylinder
3. Impression cylinder

A 4-color machine has 4 units;
A 5+ color machine includes Pantone or special coatings.

4. Drying

Depending on ink type:

• Oxidation drying (conventional inks)
• Absorption drying
• UV drying (instant)
• IR drying

5. Post-Press (Finishing)

• Lamination (mat/gloss/soft-touch)
• Spot UV / Drip-off UV
• Hot Foil / Cold Foil
• Emboss / Deboss
• Die-cutting
• Gluing
• Box assembly
• Binding (for books)

4. Materials Used in Offset Printing

Paper Types

• Bristol (250–450 gsm)
• Duplex board
• Folding Carton (GC1, GC2, GD2)
• Ivory Board
• Coated paper (Mat/Gloss)
• Kraft paper
• Recycled papers

Special Substrates

• PVC
• PET
• Metalized papers
• Synthetic papers

5. Color Management

Offset printing uses:

• CMYK (process colors)
• Pantone (PMS) for exact brand colors
• ICC profiles
• Densitometer measurements
• Color bars & registration marks

6. Advantages of Offset Printing

7. Limitations of Offset Printing

• Not cost-effective for very low quantities
• Setup time is longer
• Plate & calibration cost exists
• Color change mid-run is difficult

8. Offset Printing Machines (Popular Brands)

• Heidelberg (XL, CX series – most popular for packaging)
• Komori
• Koenig & Bauer (KBA)
• Ryobi
• Manroland