To achieve a full looking healthy hair you need to get good hair coverage from the scalp up. As a user and a person who nonstop thrive to improve I found Samson hair fibers to be the best product considering all the above: The weight was perfect some fibers penetrated the hair layers and lay nicely on the scalp. The others adhered well to the hair shafts. the fiber color blended well for the reason that your hair color can reflect on these fibers too. Samson hair fibers consisting a variety of fiber sizes, weight and color shades to achieve a balanced natural look. Not all hair fibers, thickeners, concealers alike: They are made with various materials and techniques with one common goal to achieve better hair coverage and give you a great looking hair.ToppikTM is probably the most used and known brand, Toppik is known to be made of wool (sheep hair) wool can be irritating especially in the summer time, I personally used ToppikTM and I used to go crazy not understanding why my scalp is so itchy until I found out it was made of wool. There are quiet few brands out there...I have tried them all and so my friends. Some were too dark or light but the major problem with most hair fiber brands was the size and weight of the fibers: Remember, we need the fibers to hold on to our own hair longer and better, it should also cover our scalp somehow to create an illusion of full dark hair. Some brand fibers were too heavy and could not cling to the hair for long time simply sliding down on your scalp to your forehead, neck and behind your ears (felt like sand). Some hair fibers were too light and stayed on top of your hair "bulk up" and did not penetrate deeper and the more you tried to add hair fibers it looked worse.Other brands were made of materials that did not blend into the natural hair color and feel and in certain light you could tell the obvious difference. Samson Hair fibers has all the unique characteristics to blend and look natural from the start.