Homebrew PCBs

The beige or tan colored opaque laminate is called CEM-1. It is paper 
based and easy on the drill bits. This type of laminate can be scored 
and snapped apart. Very little dust is made using this method.

G-10 and FR-4 laminates are the same except FR-4 has a fire resistant 
rating. Not much G-10 copper clad laminate is made these days. G-10 
has a white or gray colored water mark and FR-4 always has a red 
water mark. Some FR-4 will have a slight yellow color. This is used 
to block UV light in photoimageable soldermask applications and 
doesn't change the electrical properties of the material.

It's been over a year since I have purchased any laminate but the 
square foot price I paid was $2.35 for FR-4 and around $1.50 for CEM-
1. This was for 36" x 48" sheets and 18" x 24" panels. 

Hope this info helps.

Tom