Rack assembly for displaying curtain

A rack assembly for displaying a curtain, comprising:

• at least a rail member;
• and
• a plurality of stretching members movable configured on said rail member, each stretching member connected to said curtain;
• wherein each rail member comprises
• two or more column elements, each column element having a plurality of connection grooves and sliding grooves, said connection grooves facing different directions, and each stretching member moveably attached to said sliding grooves;
• a positioning piece having at least two through positioning holes and two rails along an upper edge and a lower edge of said positioning piece;
• a sliding piece slidably inserted between said upper and lower rails of said positioning piece, said sliding piece having an extension section, a first track and a second track being configured on said sliding piece and said extension section, respectively, and said first and second tracks being embedded into two of said plurality of said connection grooves of a respective column element, respectively;
• a plurality of connection elements, each connection element having a notch at a top end, a through hole at a bottom end, and connection blocks at lateral ends, said connection elements being vertically stacked and positioned between said two or more column elements which are adjacent by embedding said connection blocks into corresponding connection grooves of said two or more column elements, respectively;
• and
• a plurality of fastening elements, each connecting two vertically adjacent connection elements through said notch and said through holes of said connection elements.