The phrase "art thick with" is spelled with the /θɪk/ pronunciation, which involves the voiceless dental fricative sound. This sound is created by placing the tip of the tongue between the upper and lower teeth and blowing air through the small gap. The word "thick" is spelled with this sound because it contains the letter "th," which is commonly used to represent the dental fricative. When saying "art thick with," it is crucial to pronounce the /θɪk/ sound correctly to ensure proper communication.