날뛰어의 심한 단판끼리를 접목해 맞추면, 날뛰어에 의해 접합면이 떨어져 버리거나 혹은 접합면이 떨어지지 않아도, 이들 날뛴 단판을 이용하여 제조한 합판, LVL 등의 제품은 상기 날뛰어가 영향을 주고 제품자체에도 날뛰어가 발생해 버려, 상품 가치가 낮은 것이 되어 있었다.단판을 접목해 맞출 때, 접목해 맞추는 한편의 단판의 나무의 바깥쪽과 다른 한쪽의 단판 나무 안쪽이 동일면이 되도록 각각의 단판 접합면을 일치시킨 후, 압 맺고 단판의 접목해 맞춤을 한다.
To prevent warpage from developing in a joined veneer by a method wherein both end parts of respective veneers are worked into joint surfaces, onto which adhesive is applied, so as to match the joint surface worked on the face side of one veneer to be joined with that worked on the backside of the other veneer to be joined into the one and same surface for tightening under pressure.  Both end parts of veneers to be joined together are worked into joint surfaces with a joint surface working device. Onto at least one of the worked joint surfaces, adhesive is applied with a coating device. The back end joint surface of the preceeding veneer is matched with the front end joint surface of the following veneer with a matching device so as to have one and same surface on the face side of the preceeding veneer, on which adhesive is applied, and on the backside of the following veneer, on which adhesive is applied. Then, with a pressurizing device, the matched joint surfaces are tightened under pressure. Accordingly, even if the veneers to be joined warp when dried, the warpages of respective veneers act so as to cancel each other, resulting in making warpage difficult to develop in the joined veneer.