- Figures should be numbered in the order they are first mentioned in the text, and uploaded in this order.
- Figures should be uploaded in the correct orientation.
- Figure titles and legends should be provided in the main manuscript, not in the graphic file.
- Figure keys should be incorporated into the graphic, not into the legend of the figure.
- Each figure should be closely cropped to minimize the amount of white space surrounding the illustration. Cropping figures improves accuracy when placing the figure in combination with other elements, when the accepted manuscript is prepared for publication on our site. For more information on individual figure file formats, see our detailed instructions.
- Individual figure files should not exceed 10 MB. If a suitable format is chosen, this file size is adequate for extremely high quality figures.
- Please note that it is the responsibility of the author(s) to obtain permission from the copyright holder to reproduce figures (or tables) that have previously been published elsewhere. In order for all figures to be open-access, authors must have permission from the rights holder if they wish to include images that have been published elsewhere in non-open-access journals. Permission should be indicated in the figure legend, and the original source included in the reference list.
Detailed guidelines for the following types of figure are available.
Supported file formats
The following file formats can be accepted. Detailed information for each file type can be found by clicking on individual links.
- EPS (suitable for diagrams and/or images)
- PDF (suitable for diagrams and/or images)
- Microsoft Word (suitable for diagrams and/or images, figures must be a single page)
- PowerPoint (suitable for diagrams and/or images, figures must be a single page)
- TIFF (suitable for images)
- JPEG (suitable for photographic images, less suitable for graphical images)
- PNG (suitable for images)
- BMP (suitable for images)
- CDX (ChemDraw - suitable for molecular structures)
- TGF (ISIS/Draw - suitable for molecular structures)
Image formats - bitmap and vector
The type of file suitable for a figure depends on the content of that figure. Some formats are better for line drawings, such as diagrams or charts, while other formats are more suitable for photographs. There are two basic types of image format:
Bitmap images
Bitmap image files can be created and manipulated using image-editing programs such as Adobe Photoshop or the open-source alternative GIMP. Bitmap images have the following properties:
- consist of thousands/millions of pixels;
- have limited resolution (i.e. will not look sharp at high magnifications);
- are mainly suitable for photographs;
Bitmap file formats include - PNG, TIFF, JPEG, BMP.
Vector images
Vector images can be created and manipulated using a wide range of programs, including Adobe Illustrator, Macromedia Freehand, Microsoft Word and Microsoft Powerpoint. In many cases they can also be created by printing to a PDF file. Vector images have the following properties:
- consist of mathematically defined shapes (lines, curves, polygons).
- will retain their sharpness even when greatly magnified or when printed (see illustrations below);
- are suitable for images containing text- or line-based elements such as charts, graphs and diagrams;
- can contain bitmap elements;
Vector file formats include - EPS, PDF, DOC, PPT.
Bitmap figure
Vector figure
Figure size and resolution
Figures are likely to be resized on publication of the final full text and PDF versions to conform to the BioMed Central standard dimensions, which are detailed below.
Figures on the web:
- width of 600 pixels (standard), 1200 pixels (high resolution).
Figures in the final PDF version:
- width of 85 mm for single column;
- width of 176 mm for double column;
- maximum height of 230 mm for figure and legend;
- image resolution should be approximately 300 dpi (dots per inch) at the final size.
Illustrations should be designed such that all information is legible at these dimensions. All lines should be wider than 0.5 pt when constrained to standard figure widths.
Fonts
- BioMed Central recommends the use of either Arial or Helvetica fonts using 12pt characters for text within figures.
- Courier may also be used if a monospaced font is required (for example, in sequence alignments).
- Where Greek, mathematical or other special characters are needed and cannot be inserted in Arial or Helvetica, Symbol or Mathematical PI is recommend.
- Text should be designed to be legible when the illustration is resampled to BioMed Central's standard sizes listed above.
- All fonts should be embedded.
Figure file compression
Figures submitted to BioMed Central should be submitted with as small a file size as possible. Individual figure files should not exceed 10 MB. This reduces the time taken to upload files during submission and for referees and readers to download the complete article. Depending on the types of figure, the following guidelines should be considered. Further details can be found in the section on figure file formats.
- Vector figures should if possible be submitted as PDF files, which are usually more compact than EPS files.
- TIFF files should be saved with LZW compression, which is lossless (decreases file size without decreasing quality) in order to minimize upload time.
- JPEG files should be saved at Maximum quality.
- Conversion of images between file types (especially lossy formats such as JPEG) should be kept to a minimum to avoid degradation of quality.
Figure legends
Figure legends should be included in the main manuscript text file rather than being a part of the figure file. For each figure, the following information should be provided at the end of the manuscript text, following the references:
- Figure number (in sequence, using Arabic numerals - i.e. Figure 1, 2, 3 etc.)
- Short title of figure in sentence case (maximum 15 words - required)
- Detailed legend (up to 300 words - optional)
e.g.
| Figure 7. Effect of nocodazole and ammonium chloride on PCSK9-mediated degradation of the LDLR. HepG2 cells were cultured in media supplemented with nocodazole (20 μg/ml) or ammonium chloride (NH4Cl, 10 mM) for 30 min. The media were then replaced with conditioned media from HepG2 cells transiently transfected with D374Y-PCSK9-FLAG plasmid or with empty plasmid, already containing ammonium chloride or nocodazole, and the incubation was continued for 3 h. The conditioned media had also been added ammonium chloride or nocodazole. Cell membranes were isolated and membrane proteins equivalent to 10 μg were subjected to western blot analysis to determine the amount of LDLR. The amount of transferrin receptor (TFRC) was used as a control. Band intensities were quantified using a ChemiDoc XRS and Quantity One version 4.4.0 software. Results represent the mean (± SD) of four experiments, from which one representative western blot is shown. |
Scheme legends
Chemical scheme images, unlike figures, are included as part of the manuscript. Scheme legends should appear immediately after the scheme in the text - they should not form part of the embedded scheme image. Please include a legend comprising:
- scheme number (in sequence, using Arabic numerals - i.e. Scheme 1, 2, 3 etc.)
- short title of scheme, in sentence case (maximum 15 words - required)
- detailed legend (up to 300 words - optional)
e.g.
Scheme 1. Synthetic sequence to tetrahydropyridine compounds.
A full list of reagents and conditions..... |
Electronic manipulation of images
Enhancement of digital images using image-editing software can increase clarity of figures and is acceptable practice, if carried out responsibly. It is crucial, however, that artefacts are not introduced and the original data are not misrepresented. Details of significant electronic alterations to images must be given in the text of the article. Original, unmanipulated source images should be retained by the author, as BioMed Central will support requests from referees to view the original files.
Useful software
There are many software packages capable of converting to and from the major graphics formats.
Good general tools for image conversion and enhancement include Adobe Photoshop (Mac/Windows), GraphicConverter (Mac only), PaintShop Pro (Windows only).
A variety of cross-platform open-source sofware is also available for this purpose, including ImageMagick, GIMP, and ImageJ. Each of these packages runs on Mac,Windows and Linux.
Frequently asked questions
1) How do I embed fonts in a PDF?
If your figure uses non-standard fonts, it is important to ensure that they are embedded in the PDF. Using Adobe Acrobat Distiller, this is controlled through the 'Job Options' menu. Other software for creating PDFs generally offers the option to embed fonts in a similar. Refer to your software packages documentation.. Further instructions for generating PDF files are available
here
2) What do I do if my figure is larger than one page?
If it is not possible to scale your figure onto a single page we recommend that you submit and refer to it as an additional data file rather than a figure. You may wish to include some part of it (for example, a single panel or an appropriate segment) as a figure to bring the data to readers' attention and then refer to the complete version as the additional file. Please remember to remove the legend from the list of figures (renumbering the remaining figure legends, if necessary), move the legend to the list of additional files, and renumber the citations in the text.
3) What should I do if my figure is split into separate parts, 1a, 1b and 1c?
BioMed Central requires that multipart figures be submitted as a single composite image file. Please combine the separate parts of your figure into one single file, if possible using the same software that was used to create the individual parts. If the panels of the figure were created using different software, use either Microsoft Word or a graphics-creation program to produce the composite figure and submit as DOC, PDF or EPS. If large subsections of the figure cannot be combined (e.g. because the final file size would be too large), please submit these as separate figures and renumber them appropriately.
4) What should I do if my figure exceeds the 10 MB submission limit?
All figures and additional files submitted to BioMed Central must be below 10 MB in size. This file size is sufficient for very high resolution, print publication quality images, if suitably prepared. There are a number of reasons why figure file sizes may be unnecessarily large. In some cases, unnecessary conversion between file types may cause figure file size to grow, so going back to the original source may help. If your figure is a TIFF, try resaving as a compressed TIFF (
more information). If it is a photographic image, consider resaving it as a high quality compressed JPEG. If your figure is an extremely complex vector diagram or plot, it may be necessary to convert it to a bitmap (
more information).
5) Why must I submit figure files separately from the manuscript? Why can't I submit a single composite manuscript file containing everything?
A number of versions of an article are required at different times: the manuscript sent to reviewers; the version published on acceptance; the final full-text web and PDF versions. For each of these stages BioMed Central uses automated processes to assemble the manuscript and include and label the figures appropriately. The automated processes require figures to be submitted separately.
If you have other questions or are experiencing a particular problem with figures, please contact the BioMed Central production team at edproduction@biomedcentral.com.
Illustrations and figures: 
