get item from collection that match
$artist = 'Vincent John Doe';
// you can filter the collection and keep only those items
// that pass a given truth test:
$art_collection = $paintings->filter(function ($painting) use ($artist) {
return $painting->artist == $artist;
});
// you can also do a foreach
foreach($paintings as $painting) {
if($painting->artist == $artist) {
$art_collection[] = $painting;
}
}