KESTABILAN KUALITAS WARNA KHUSUS PADA MESIN SM-52 SPEEDMASTER DI PT. SUBUR MITRA GRAFISTAMA

This research aims to analyze the color quality stability of special prints on the SM52 Speedmaster printing machine at PT Subur Mitra Grafistama. The main problem
identified is the color instability of the prints, which can affect the quality and
increase the number of defective products. This research focuses on measuring and
analyzing the density value and L*a*b value for the special color (gray) on the
cover print. The methodology used includes observation, interviews, and literature
studies, with data obtained during the implementation of Industrial Practices at the
company. The results showed that the stability of density values and L*a*b values
for special colors on cover prints can be influenced by various factors such as paper
quality, printing plates, Testing the characteristics of the ivory material for gray
cover molds shows grammage, thickness, brightness, opacity and oil absorption.
Testing using 65x92 mm ivory paper. The test results show the average standard
deviation values: 196.45 ±3.49 g/m2 for grammage, 220.1 ±6.57 mm for thickness,
108.40 ±0.24 % for brightness, 100 % for opacity, 19.79 ±1.19 mm-1 for oil
absorption capacity (F), and 24.18 ±0.89 mm-1 for oil absorption capacity (W).
For stable color density on PT book cover printing. JING SI MUSTIKA ABADI
INDONESIA in the first printing was stable but in the 500th and 1751st printings
the printing was unstable. For stability in L*a*b the value of a in the printing was
unstable because in the 1251st printing the color of the printing increased
Keywords: graphics industry, offset printing, testing
Penelitian ini bertujuan untuk mengidentifikasi kestabilan kualitas warna cetakan
khusus pada mesin cetak SM-52 Speedmaster di PT. Subur Mitra Grafistama.
Masalah utama yang diidentifikasi adalah ketidakstabilan warna pada hasil cetakan,
yang dapat mempengaruhi kualitas dan meningkatkan jumlah produk cacat.
Kestabilan warna cetakan ditentukan berdasarkan nilai density dan nilai L*a*b.
Metodologi yang digunakan meliputi observasi, wawancara, dan studi pustaka,
dengan data diperoleh selama pelaksanaan Praktik Industri di perusahaan tersebut.
Produk cetak yang diamati adalah produk cover buku warna abu-abu yang dicetak
pada kertas ivory ukuran 65x92 cm dengan karakteristik gramatur (196,45 ±3,49)
g/m2, ketebalan (220,1 ±6,57) mikron, brightness (108,40 ±0,24) %, opasitas
100, daya serap minyak (19,79 ±1,19) mm-1 untuk sisi Filt (F) dan (24,18 ±0,89)
mm-1 untuk sisi Wire(W). PT JING SI MUSTIKA ABADI Hasil pengujian
kestabilan density warna cenderung stabil namun terjadi penurunan nilai density
pada cetakan ke 500 dan 1751. Sementara hasil pengujian L*a*b, nilai a pada
cetakan tidak stabil yang terlihat pada cetakan ke 1251, nilai a meningkat.
Kata kunci: industrigrafika, cetak ofset, pengujian