Composite colored aggregate and weather‑resistant binder compose core of granite paint. Low‑quality product uses poor‑weather‑resistance color sand and weak binding resin. After ultraviolet radiation, color sand fades and binder loses bonding power, leading grain shedding on wall surface. Qualified granite paint adopts stable inorganic color sand matched with outdoor‑special weather‑resistant emulsion. Buyers should pay attention to aggregate anti‑fading performance and binder aging‑resistant technical index.

Single‑component raw‑material index cannot represent final finished coating performance. The complete system including primer, intermediate granite paint and top protective coat decides long‑term outer‑wall service result. Some buyers only check middle‑layer granite paint sample, ignoring matching primer and clear top coat. Protective top coat plays critical role for anti‑aging and anti‑stain. Request full‑system aging test report covering primer intermediate coat and top coat for comprehensive reference.

Urban atmosphere contains dust, automobile exhaust and acid rain. Exterior wall granite paint faces continuous pollution impact. Inferior product absorbs pollutant firmly, facade becomes dark and mottled after several seasons. High‑quality protective top coat lets contamination stay on surface and be washed away by rainfall. Simulated anti‑stain test can simulate real urban pollution condition. Anti‑stain performance directly influences building long‑term visual appearance and maintenance workload.

Granite paint system needs good adaptability for different exterior wall base including concrete, cement mortar and old renovation wall. Loose or high‑alkali old wall must rely on functional primer to stabilize base condition. If primer formula does not match base situation, later‑period blistering and peeling risk rises sharply. Project buyers should clarify wall alkali level and base firmness, and confirm complete supporting coating solution together with supplier.

Large building facade requires multi‑batch supply of granite paint. Color sand particle proportion, grain size distribution and color tone must keep stable among different batches. Slight particle or color deviation will produce obvious patch‑shaped defect on large outer wall. Before formal bulk delivery for big project, lock reference sample board. Arrive at clear agreement about batch inspection standard with supplier to avoid visual difference after construction completion.