Angles in linear-gradients and concrete object size

Example 1:

background: 
linear-gradient(0deg, transparent 25%, rgba(0,0,255,0.5) 25%, rgba(0,0,255,0.5) 75%, transparent 75%), 
linear-gradient(-90deg, transparent 25%, rgba(0,0,255,0.5) 25%, rgba(0,0,255,0.5) 75%, transparent 75%), 
linear-gradient(-45deg, transparent 25%, silver 25%, silver 75%, transparent 75%), 
white;

Example 2:

background: linear-gradient(0deg, transparent 50px, rgba(0,0,255,0.5) 50px, rgba(0,0,255,0.5) 150px, transparent 150px), 
linear-gradient(-90deg, transparent 50px, rgba(0,0,255,0.5) 50px, rgba(0,0,255,0.5) 150px, transparent 150px), 
linear-gradient(-45deg, transparent 50px, silver 50px, silver 150px, transparent 150px), 
white;

background-position: center, center, 0px 0px;
background-size: auto 100px, auto 100px, auto 100px;

Example 3:

background: linear-gradient(0deg, transparent 50px, rgba(0,0,255,0.5) 50px, rgba(0,0,255,0.5) 150px, transparent 150px), 
linear-gradient(-90deg, transparent 50px, rgba(0,0,255,0.5) 50px, rgba(0,0,255,0.5) 150px, transparent 150px), 
linear-gradient(-45deg, transparent 50px, silver 50px, silver 150px, transparent 150px), 
white;

background-position: center, center, 30px 30px;
background-size: auto, auto, auto 70px;

Example 4:

background: 
linear-gradient(0deg, transparent 50px, rgba(0,0,255,0.5) 50px, rgba(0,0,255,0.5) 150px, transparent 150px), 
linear-gradient(-90deg, transparent 50px, rgba(0,0,255,0.5) 50px, rgba(0,0,255,0.5) 150px, transparent 150px), 
linear-gradient(-45deg, transparent 50px, silver 50px, silver 150px, transparent 150px), 
linear-gradient(-135deg, transparent 50px, silver 50px, silver 150px, transparent 150px), 
linear-gradient(-225deg, transparent 50px, silver 50px, silver 150px, transparent 150px), 
linear-gradient(-315deg, transparent 50px, silver 50px, silver 150px, transparent 150px), 
white;

background-position: center, center, 30px 30px, 100px 30px, 100px 100px, 30px 100px;
background-size: 200px 100px, 100px 200px, 70px 70px, 70px 70px, 70px 70px, 70px 70px;
background-repeat: no-repeat;