  Based on the findings of stripe skyrmions and the metastability of a state of
an arbitrary number of skyrmions, precisely controlled manipulation of stripe
skyrmions in pre-designed structures and mutual transformation between helical
states and skyrmion crystals (SkXs) are demonstrated in chiral magnetic films.
As a proof of the concept, we show how to use patterned magnetic fields and
spin-transfer torques (STTs) to generate nematic and smectic stripe phases, as
well as "UST" mosaic from three curved stripe skyrmions. Cutting one stripe
into many pieces and coalescing several skyrmions into one by various external
fields are good ways to transform helical states and SkXs from each other.
