Recto and Verso: The Pictorial Fronts and the Marbled Reverses of Two Flemish Panel Paintings

From the first third of the 15th century onwards, panel paintings with marbled reverses increasingly appeared in Flemish art. The fronts of these panels primarily depicted religious narrative scenes or portraits. The backs were decorated with an abstract pattern, referred to as marbling. These painted marble facsimiles often differed in terms of design from other examples of stone imitations such as those used on the frame decorations of other panels. Unlike these frames, which suggest a greater illusionistic intention, the marbled reverses appear to function as abstract ornamentation. However, this article proposes that the painted backs are thematically linked to the pictorial narratives of the fronts. The marbled backs of Rogier van der Weyden’s Crucifixion and the Portrait of Margareta van Eyck will be considered in the context of a profane and a theological iconography. Both panels feature a reverse that can be identified as both an imitation of red porphyry and a representation of liquid paint. Metaphysical, material–semantic, and theological references will be revealed in the pictorial examples.

QUALITY CONTROL OF HORIZONTAL ROAD MARKING APPLICATION DURING CERTIFICATION OF MARKING MACHINES

Horizontal road marking along with road signs is an essential factor that ensures road safety. The quality of road markings largely depends on the quality of the application. In today’s, for road marking are used road marking machines. They are complex high-performance automated units requiring highly professional operators. Stink to classify for the way of marking, design of the running gear, base machine, type of drive, productivity and the most important signs. The article describes the principles of the operation of marking machines and the main technical characteristics of machines from leading manufacturers: GRACO, SТiM, Hofmann. When applying road marking, special attention should be paid to the use of certified materials and certified equipment. The results of measuring the geometric and lighting indicators of horizontal road marking are presented. During certification, marking is applied with a marking machine. During the application, the thickness of the liquid paint layer is determined by a calibrated comb. To control the lighting technical characteristics of road marking – whiteness, retroreflectivity (Rl) and brightness (Qd) coefficients, a ZRM 1021 reflectometer and a ZRM 1013 retroreflectometer are used. Geometric indicators were measured with a tape measure. The table of certification results of the Line Lazer IV 3900 machine is shown. Similar indicators were obtained during certification of the machines of Hofmann, Combizet Gruen, RoadLazer, etc. Deviations from the road marking indicators declared by the manufacturer are not observed for 3 years. All marking performed by verified marking machines meets the requirements of current regulations. Keywords: certification of machines, durability of marking, retroreflectivity, accuracy of application, brightness.

Pengaruh Suhu Dan Waktu Tinggal Terhadap Kecenderungan Menguning Pada Proses Produksi Alumunium Fasad

Painting using paint powder is one of the techniques of protection against corrosion are evolving rapidly. Powder paints have aesthetic value approaching liquid paint as well as durability and relative utilization is better than liquid paint. The process of maturation of the paint powder that is only done with the process of warming at a certain temperature and a certain span of time. Standard maturation process known as maturation curve (curing folder). The difference in temperature and time against standard value ranges of risk occurrence of color change especially in white color (light). Therefore, do the research to find out the influence of temperature and time of warming up against the tendency of yellowing in white powder paint. Colour measurement is performed using a colorimeter in units of CIE Lab. Value b in CIE lab color trend show the yellowish or bluish. Temperature and time of warming up is the variable factor research determined 5.Keyword : paint powder, maturation, temperature, color. Pengecatan menggunakan cat bubuk merupakan salah satu teknik perlindungan terhadap korosi yang berkembang secara pesat. Cat bubuk memiliki nilai estetika mendekati cat cair serta daya tahan dan utilisasi yang relative lebih baik dibanding cat cair. Proses pematangan cat bubuk yang hanya dilakukan dengan proses pemanasan pada suhu tertentu dan rentang waktu tertentu. Standard proses pematangan dikenal dengan kurva pematangan (curing map). Perbedaan suhu dan waktu terhadap rentang nilai standard menimbulkan resiko terjadinya perubahan warna khususnya pada warna putih (terang). Oleh sebab itu dilakukan penelitian untuk mengetahui pengaruh suhu dan waktu pemanasan terhadap kecenderungan menguning pada cat bubuk warna putih. Pengukuran warna dilakukan dengan menggunakan colorimeter dalam satuan CIE Lab. Nilai b pada CIE lab menunjukan kecenderungan warna kekuningan atau kebiruan. Suhu dan waktu pemanasan merupakan variabel penelitian yang faktornya ditentukan 5⁰C dan 5 menit diluar kurva pematangan. Kata kunci: cat bubuk, pematangan, suhu, warna.