Cores of known thickness reduce this to the variation in the fibreglass skins only. Tolerances are required in the design to allow for this. Fixtures for large or long structures should allow for this. Again almost unlimited possibilities. For large flat areas, a textured or semigloss is recommended to conceal possible imperfections that can show with aging.
Shrinkage can cause print through of fibres.
If a textured finish is chosen, this can have a significant influence on demouldoing and draw must consoider this. Dark colours will age faster if outside and will absorb heat affecting the expansion of the product. Metallics are possible but are difficult to apply on complex moulds without a 'shadowing' effect. Metallic paints are also extremely difficult to touch-up. The above tips are only a guideline, and cannot make up for the years of experience FDL has in this industry.