LAXTEEX SLIDES 



507 



zontally. Therefore the image must stand erect across the 

 plate. 



Various forms of mats are sold for lantern slides. These 

 are thin black paper sheets made the size of the slide on the 

 outside but have openings (round, oval, oblong 1 , etc.) of dif- 

 ferent sizes cut out of the center. In the completed slide 

 the picture is seen through the opening and the border of 



Tf 



Fig. 389. Adjustable frame for cutting lantern slide mats. About two-thirds natural size. 



the image on the screen is of the same shape as the opening 

 in the mat. It is often convenient and more satisfactory to 

 make these mats by use of a small adjustable frame (Fig. 

 389) which is laid down over the slide and adjusted to the 

 size and shape of the image desired for presentation on the 

 screen. The frame is then set (by thumbscrews) and placed 

 over a sheet of (black) paper (wrapping paper is sufficient). 

 With a penknife the opening is cut out of the paper. The 



