Streamer for both LPR and MPR rockets up to about 2.5lbs can be made from a number of common, easy to find & cheap materials.
For Light LPR models 1" surveyor's tape in a variety of colors makes excellent single or double strand streamers. For a bit larger models, a roll of 2 &3" Yellow Caution tape can be had at Lowe'for under 7 bucks. 2" to 6" Crepe paper makes awsome streamers for sport and competition rockets up to 1.5lbs. Wide 3, 4 & 5" ribbon also does a decent job for larger models up to about 2.5lbs.
There are PETF (teflon) Military grade muted color tapes from 1/4" to 2" wide on 43ft rolls that not only make wonderful Streamers but also eliminate the need for FP Wadding as well.