総説2 特集「アジアシンポジウム」
Comparison of CMYK-OGV (Expanded Color Gamut) and XCMYK (eXpanded-gamut CMYK)
2026 年 63 巻 1 号 p. 32-42
詳細
2026 年 63 巻 1 号 p. 32-42
Color accuracy and gamut are key to print quality and market appeal, but standard CMYK often struggles with vibrant hues and brand/Pantone matches, leading to higher ΔE values. Expanded Color Gamut (ECG) technologies extend the printable color space beyond standards like GRACoL 2013 and ISO 12647-2. This paper compares two ECG methods: CMYK-OGV (adding Orange, Green, Violet) and XCMYK (high-density CMYK with advanced screening). CMYK-OGV achieves up to 80-90% Pantone coverage and a 68% larger gamut than GRACoL, ideal for brand-critical designs, but requires 7-color presses, complex calibration, and higher costs. XCMYK offers a 46% wider gamut than GRACoL using only four inks, making it more economical and digital-printing compatible, though it cannot match CMYK-OGV's extreme colors. The paper evaluates workflows, benefits, and limitations to guide printers in choosing the best solution based on quality, cost, and complexity. Additionally, it highlights several technical, ink, and printing process challenges that the expand color gamut methods currently face.
