Figure 4

Opacification of paraffin block using white crayon. (s) A piece of broccoli was embedded in paraffin containing 6.25% w/w white crayon and placed on the custom-made attachment (asterisk). (b) The custom-made white attachment was designed (upper image) and made using 3D printing machine (lower image). Characteristics of the attachment are the white color and the sawtooth pattern on the top, which avoid shadows and increase the area for attaching paraffin block. (c) The border between broccoli specimen and white paraffin is apparent on the block face (upper image). When the block-face image was converted to grayscale image for volume rendering, only the cutting face of the broccoli specimen is seen (lower image). (d) The serial block-face images (270 images with a voxel size of 20 × 20 × 20 µm) were converted to grayscale images (c), then used for volume rendering (d). Bars: 5 mm. The STL file of attachments is available at GitHub