What a STUNNER! Calathea 'Thai Beauty' is a rare plant with fabulous yellow and green variegated foliage. It is a beauty! Can grow 60cm x 40cm.
Calatheas love a warm but shaded spot in greenhouses or conservatories, but anywhere indoors without cold drafts and enough light is suitable. A bright bathroom large enough to house the plant can be a good location, because of the higher moisture levels.
During the growing season water the plant thoroughly and keep the soil moist (remember this plant loves moisture). When it's winter growing slows down or stops, reduce watering and you can allow the top soil to become slightly dry between each watering. If you can - use tepid rain or distilled water and avoid cold hard water.
Misting and keeping the soil moist will help with humidity but if you can and if your plant is showing signs that it's needed - use a humidity tray or electronic humidifier. Placing the Calathea near other plants will also improve humidity.
Pictured here in a 20cm pot, this is the size of plant you will receive.