i use them to take the bulk out of crown.use longer sides that almost lay over and blend into real and fade out till and you see all u see is real at ear.i dont have a visual seam its like a blend.where it lays over my own i thin it to make it seamless not bulky like hair laying on top of hair,i use razor cutting and thinnig shears to break up bulk,if hair looks chunky at brown or front a whack of thinning shears helps in my opinion.you might get a few strays that are short i just pluck or trim.its kinda like real hair everyone has strays or little flyaways.anyway thats my trick for bulk.i dont usally expect more than 3 to 4 months max.i sacrifice longevity for a customization.im always trimming and tweaking.me and downtime equal project with old hair.you should see some of the things i make--i do eyebrows ,goatees, sideburns,i know weird but i have fun changing up my look.