Just as the prohibition of Borer applies to food, it applies to other items as well, such as books, utensils, and clothing (Taz; MB 319:15). All the above rules for Borer with food apply to other mixtures as well. In other words, one may remove from a mix something he wishes to use immediately, because this is not derekh melakha but the normal way this item is used. However, one may not remove the item in order to use it later. Similarly, one may not sort a mix, and all the more so one may not remove the items he does not want.
For example, if children mixed together pieces from different games, they may not be separated. But if the children wish to play with one of the games now, they may remove the desired pieces from the mix. This sorting is not considered derekh melakha but derekh misĥak (the normal way of playing), because a game normally begins with taking out its pieces.
There is also a problem of Borer with mixed-up silverware. Although the pieces are large and the difference between the different types of silverware is apparent, nevertheless, when there are many pieces, they are considered mixed. Therefore, one may not sort silverware and place each type separately. However, when washing the silverware, one may dry each utensil separately and place it in the proper compartment, because this does not involve selecting the utensil from the mixture in order to sort it. Rather, one is taking each piece randomly in order to dry it, and once it is in his hand he may place it in the appropriate compartment.
Before a meal, one may take the mixed-up silverware and put the appropriate pieces next to each plate. The reason is that this is not a normal way of sorting, but rather the normal way one prepares for a meal. This permission is on condition that it is done close to the time of the meal.
Borer can also apply to books. For example, if many different ĥumashim are mixed in a pile, and a synagogue attendant wishes to distribute the appropriate ĥumashim to worshipers, he may not remove the ĥumashim that are not being used from the pile. Similarly, he may not remove the appropriate ĥumashim from the pile long before the service. Rather, close to the time of services one may remove the appropriate ĥumashim from the pile, because this is not derekh borer but rather the normal way to take books to use.
Books on a shelf are not considered mixed. Therefore, one may remove books he wishes to learn from, even if he will not actually use the books until hours later. One who used many books may return them to the bookcase on Shabbat for the sake of neatness. In the course of returning them, he may put each book in its proper place (R. Shlomo Zalman Auerbach in SSK 3, nn. 220 and 239).