The ornamental design for a brush with slidablecap, as shown and described.
FIG. 1 is a perspective view of a first embodiment of a brush with slidable cap;
FIG. 2 is a front elevation view of the brush with slidable cap of FIG. 1, the back, left side, and right side views of the brush with slidable cap being identical to the front view;
FIG. 3 is an enlarged top plan view of the brush with slidable cap of FIG. 1;
FIG. 4 is an enlarged bottom plan view of the brush with slidable cap of FIG. 1;
FIG. 5 is a perspective view of a second embodiment of a brush with slidable cap;
FIG. 6 is a front elevation view of the brush with slidable cap of FIG. 5, the back, left side, and right side views of the brush with slidable cap being identical to the front view;
FIG. 7 is an enlarged top plan view of the brush with slidable cap of FIG. 5; and,
FIG. 8 is an enlarged bottom plan view of the brush with slidable cap of FIG. 5.
The broken lines showing a bristle tuft illustrate a portion of the brush with slidable cap that forms no part of the claimed design. The broken lines shown between the cap and the handle in FIG. 8 illustrate environmental structure that forms no part of the claimed design.