Answer by taking a quote from the following article:

Matthew Paris, known as Matthew of Paris (Latin: Matthaeus Parisiensis, lit. "Matthew the Parisian"; c. 1200 - 1259), was a Benedictine monk, English chronicler, artist in illuminated manuscripts and cartographer, based at St Albans Abbey in Hertfordshire. He wrote a number of works, mostly historical, which he scribed and illuminated himself, typically in drawings partly coloured with watercolour washes, sometimes called "tinted drawings". Some were written in Latin, some in Anglo-Norman or French verse.

In some of Paris' manuscripts, a framed miniature occupies the upper half of the page, and in others they are "marginal" - unframed and occupying the bottom quarter (approximately) of the page. Tinted drawings were an established style well before Paris, and became especially popular in the first half of the 13th century. They were certainly much cheaper and quicker than fully painted illuminations. The tradition of tinted drawings or outline drawings with ink supplemented by coloured wash was distinctively English, dating back to the Anglo-Saxon art of the mid-10th century, and connected with the English Benedictine Reform of the period. A strong influence on one branch of the style was the Carolingian Utrecht Psalter, which was at Canterbury from about 1000 to 1640. This was copied in the 1020s in the Harley Psalter, and in the Eadwine Psalter of the mid-12th century.  Recent scholarship, notably that of Nigel Morgan, suggests that Paris' influence on other artists of the period has been exaggerated. This is likely because so much more is known about him than other English illuminators of the period, who are mostly anonymous. Most manuscripts seem to have been produced by lay artists in this period. William de Brailes is shown with a clerical tonsure, but he was married, which suggests he had minor orders only. The manuscripts produced by Paris show few signs of collaboration, but art historians detect a School of St Albans' surviving after Paris' death, influenced by him.  Paris' style suggests that it was formed by works from around 1200. He was somewhat old-fashioned in retaining a roundness in his figures, rather than adopting the thin angularity of most of his artist contemporaries, especially those in London. His compositions are very inventive; his position as a well-connected monk may have given him more confidence in creating new compositions, whereas a lay artist would prefer to stick to traditional formulae. It may also reflect the lack of full training in the art of the period. His colouring emphasises green and blue, and together with his characteristic layout of a picture in the top half of a page, is relatively distinctive. What are probably his final sketches are found in Vitae duorum Offarum in BL MS Cotton Nero D I.

Did Paris often work alone?