All blinds with slats will let in some light through the spaces between slats.
Do wood blinds block light.
According to the window designers choosing the smaller slat sizes will lower this risk while creating tighter closure.
Their cell pockets trap heat and light between them besides lending you the privacy that you desire at all times during the day.
Also you have to keep in mind that it is block out all light is an impossible thing to do no matter how effective your shutter are.
Well this is possible but your room has to have no doors or windows.
Light gaps are especially problematic on blackout shades where complete darkness is desired.
Light filtering blinds diffuse the harsh sunlight into soft rays room darkening blinds to block out most of the light and blackout treatments are built to obstruct all the light making any space dark.
Are faux wood blinds room darkening.
Ways to prevent the excess light.
Light blocking strips can cover gaps.
Although there are some blinds with fold flat slats that close tighter to block more light if you want to block a lot of light you re better off with shades.
Roller shades naturally have large gaps to the sides of the fabric so these light blocking strips are the perfect solution for maximum light control.
Link to other question.
Basically they can really block a substantial amount of outside light from coming into your room or area.
Window treatments come in various fabric options which include sheer light filtering room darkening and blackout materials and depending on your requirements you can choose the right one.