Subject matter covered was eclectic; lots of contemporary arts and crafts side by side with historic articles on Old Masters, old furniture, Japanaese tobacco boxes, Architecture, gardens, Maori Art...There are reminiscences and memorials to those who've died- Mortimer Menpes on Whistler, Memorials of Aubrey Beardsley etc.
Illustrations were either incidental to the text in black & white photographs, or as "supplements" many of which were specially prepared by the artist. Many of those were in colour or lithography. The Studio was one of the first magazines to use photomechanical reproduction. As those suppements were a on special papers (sometimes even tissue or waxed paper) and printed one sided, it's a fair guess that many were destined for framing.
Bound editions (very heavy duty- olive green cloth covered with gilding) were designed for library or personal use where they provided much comfort and joy (they still do!)
My own copies all come from the first two decades. I don't have any of the most coveted special issues on jewellery, fans, photography, but those I do have provide endless snippets and surprises as well as sustained information. I've found picures of early Cecil Aldin paintings, furniture by Gimson, Ambrose Heal, pottery by Howson Taylor, Royal Copenhagen, Howard Stabler... Larger articles on Jessie King, Cranston Tea Rooms by Charles Rennie Mackintosh, numerous ones on J McNeill Whistler delight.
Some of the recurrent names appearing have now lost their glamour (to be regained)- Frank Brangwyn, E Boroughs Johnson, Alfred East, Nico Jungman, Kossiakov, Alexander Fisher. Others mentioned will become much bigger- Lutyens, Gertrude Jekyll, Beardsley, Annie Macbeth, Ambrose Heal, Jessie King, Lalique, Galle,