Mushroom at 375 GSM provides meaningful light reduction without full blackout. When drawn, a Mushroom panel creates a dimmed, warm-toned atmosphere — the color contributes to this by absorbing rather than reflecting the light that passes through. For a bedroom where early morning light is a consideration, the effect is a comfortable dim rather than complete darkness. For full blackout, a lining added at order time is the recommended solution. For most daytime uses — privacy, glare reduction, general comfort — 375 GSM is highly effective.