Juno White J33 Wall & Ceiling Paint Reviews

Professional-Grade Coverage for Demanding Surfaces J33 Opak is a high-performance water-based emulsion paint developed for professional results on both interior and selected exterior surfaces. Engineered with acrylic copolymers in aqueous dispersion, this formulation provides high opacity and a rich, extra-matt finish that effectively conceals imperfections, particularly over large, light-sensitive areas. Ideal for use indoors on walls and ceilings, particularly in new builds or renovations where smooth and even finishes are required. Its excellent hiding power and whiteness make it well-suited for office buildings, commercial spaces, and residential interiors. It may also be used externally on vertical masonry, such as façades, and warehouses - provided these are located in temperate, dry climates and protected from severe weather conditions. It can also be used on patios in areas subject to occassional, light foot traffic. Key Features and Benefits Outstanding whiteness and hiding power Extra-matt finish hides surface blemishes and uneven light reflection Class 1 wet-scrub resistance and easy cleanability Breathable finish supports long-term surface durability Anti-mould protection for healthier environments Non-splatter formulation for cleaner on-site application Excellent adhesion on mineral substrates like plaster, cement, and concrete Certifications and Performance Standards J33 Opak meets key professional benchmarks, including: Fire Retardant on non-combustible substrates: Certified B-s1, d0 according to EN 13501-1:2007+A1:2009 Class 1 wet-scrub resistance (UNE-EN ISO 11998:2007) Class 1 opacity performance (UNE-EN ISO 6504-3:2007, Method B) Surface Preparation and Priming Apply only to clean, dry, and structurally sound substrates. Allow fresh cementitious surfaces to cure for at least 30 days. For interior use, seal porous or dusty surfaces with Hidrocril or Primerlite. On exterior masonry, use Primerlite for best adhesion and durability. New plaster or gypsum must be sealed before painting. Painted surfaces should be sanded to remove gloss and ensure compatibility through a patch test before full application. For treating mould contamination, the technical team advises using N-Virol Suretherm Goodbye Mould Cleaning Spray. Always refer to the relevant data sheet before use. If unsure, seek guidance before application. Application Guidelines Stir thoroughly before use. Apply using brush, roller, or spray in conditions above 5ºC, with relative humidity below 80%. Ensure the substrate temperature is at least 3ºC above dew point. Do not apply in conditions where rain, strong wind, or high humidity are likely during drying. Allow at least 4 hours between coats. For best results, apply two full coats. Clean tools immediately after use with soap and water. Restrictions and Limitations Do not apply on hot substrates or during risk of rain Must not be used on damp or unstable surfaces If splashed before drying, may cause surface staining (“snail trails”) Do not use any additives that are not specified in the technical datasheet. Always store in a cool, frost-free environment and use appropriate PPE during preparation and application. Important Notice Always refer to the latest Technical Datasheet for detailed preparation, application, and safety information. This ensures compliance with regulations and guarantees the best results.